Total Exchange Capacity = 9.04

-a little lower than normal? I did a soil jar test the other day and it came back as a sandy loam soil...

pH = 5.7

-really low (should be 6.2 to 6.8)

Organic Matter = 3.13%

-low, so hopefully Milorganite and mulching the grass and leaves this year will help

Sulfur = 9 ppm

-ok, but should be slightly higher (10 to 20 ppm)

Phosphorous = 186

-not bad, I believe you said that 200 was optimal for grass though you’ve gone much higher, so that would probably be easy to get up to optimal levels

Calcium = 61.39%

-slightly low, want to get it to 65-70%, so perhaps some Mag-I-Cal will be needed

Magnesium = 6.5%

-pretty low (optimal is 10 to 20 right?), but not sure what would be needed to raise it

Potassium = 1.51%

-really low, so I’m seeing applications of potassium sulfate in my future (I also have starter fertilizer if needed for the overseeding)

Boron = 0.27 ppm

-really low, should be around 0.7-0.8 ppm, so 20 Mule Borax?

Iron = 277 ppm

-not too low, 300’s optimal so with the Moss Control and Milorganite I don’t see a problem there

Zinc = 23.18 ppm

-don’t have any notes on zinc!

Aluminum = 772 ppm

-don’t have any notes on aluminum either!

Perfect, just what I was hoping for and I really enjoyed the reasonings as to why! Thank you so much morpheus!

1) I do plan on taking 100 soft from the backyard and turning that into a vegetable garden (and am looking to sow some seeds as soon as this darn snow melts!). There is also a strip along the driveway that I'm looking to grow some flowers.

Will I need to treat it differently with your recommendations or are certain steps not safe to be adding with the growing vegetables/flowers?

2) I remember reading one of your posts months ago about mixing Boron slowly and by hand into the Milorganite, but if you don't mind do you think you could refresh my memory haha

3) If I decide to go with milorganite feedings instead of the synthetic for the spring applications, will the milorganite provide enough potassium?

4) I'm planning on overseeding in August, therefore would I need to make any changes to your guidelines? Such as applying some synthetic starter fertilizer after the seedlings have germinated and grown for a few weeks?

And yeah, Jonathan Green has changed it to Mag-I-Cal, guess they though it was more clever!

1) Treat the gardens the same as the grass; all recommendations are safe for flowers, vegetables, lawn, and so on.

1a) Flower gardens depend on enormous amounts of phosphorus to grow and blossom, and I've balanced my flower gardens over 1,000 PPM. For these, feed monthly at bag rate (about 4 pounds per thousand square feet) with any good starter fertilizer for this year only, then twice a year (May and July) thereafter. Milorganite at other times is always appreciated by the flowers as well.

1b) Too much phosphorus makes vegetables chewy, stringy, and bitter. Balance these the same as the lawn, so around 200 PPM, for the generic vegetable garden (actual requirements vary per species). While Milorganite can be used and has never caused a problem, consider that it's processed human poo. This squicks some people out.

2) Sure! In a wheelbarrow or the like, dump the Milo. Spraying very, very lightly with water (I use a spray bottle like the kind people use to damp their clothes when they iron) will help the boron stick. Add the recommended amount of boron and stir, spraying occasionally to get the stuff to stick to the Milo. Then apply over the recommended area. So if going for bag rate Milorganite (1 bag per 2,500 square feet), you'd add 10 tablespoons of 20 Mule Team Borax.

Apply carefully, making sure that you're going at very close to bag rate. Overapplication of boron will cause problems, although I did build in a lot of error margin. I'd rather see the boron levels rise slowly over several years than see you overapply.

3) Nope. Potassium levels in Milorganite are less than 1% However, you can either use your moss killer (16% potash equivalent) as outlined above, or I can redo the numbers for potassium sulfate if you want to purchase that.

4) I accounted for the seeding in the schedule, so no shifts are necessary. If you want to drop another starter application when seeding, that's fine by me and it'll kick your soil over to having greater margin in P. However, your P levels are actually just fine for seeding (or will be after one application). P has a very wide zone of luxury consumption before it becomes toxic, so application won't hurt anything...but it won't help much, either.

That's why I recommended an organic application at that time (corn, soy, Milorganite, whatever). Decay will be slow enough that it's still in full swing when the grass gets old enough to want it.

Extra Credit) Turns out there's a certain...male enhancement pill...by the name of Mir-A-Cal. So I can see why they changed their name on that stuff!

My stars, I realized I skipped:

Aluminum 772: OK, so maybe you do have some of the lighter clays in your soil, or just naturally high aluminum levels.

Al is toxic to plants and serves absolutely no purpose we've discovered in the plant. However, it's bound into inaccessible compounds at pH levels over 5, and generally won't cause real issues until pH falls under 4.5. Of course, at those pH levels, you already have many problems and aluminum probably isn't your worst one at that point.

Fixing aluminum toxicity is quite easy--raise the pH to bind it up. In your case, although somewhat high, this is already bound and not causing any problems. Nor is it ever likely to cause any problems.

Hydrangea sites often recommend the use of aluminum sulfate to change the colors of hydrangea blossoms to blue. I don't recommend doing this as you can render the soil toxic to other plants (hydrangea are extremely aluminum tolerant). Instead, if you prefer blue hydrangea, use iron sulfate. Toxicity from iron is nearly impossible to achieve in the first place. Plus avoid the use of phosphorus, which will turn the hydrangea pink if enough is used even in intensely acidic soils.

Fun fact: By applying phosphorus to one side of the plant and iron sulfate to the other, you can grow a hydrangea that has half blue and half pink blossoms (although neither color is intense). I did it once, but it requires a lot of attention and effort.

So extra phosphorus for the flowers, but the veggies get treated like grass... got it!

I forgot that the moss killer had potassium, so it's great that I can double dip and use it for two issues! Thanks for noticing that!

What's the best way to spread the epsom salt? Would I be able to mix it into the Milorganite along with the Boron?

I'll probably end up using Milorganite at the time of seeding and for all of the other organic feedings that you listed. I was wondering when I could squeeze in an application of cracked corn? I know you mentioned in my other thread that it would be a good idea since it would help in preventing fungal diseases throughout the summer? Could I put it down when I apply the Mag-I-Cal on April 1 or is that too early? Or should I wait until after my first Milorganite treatment, when the soil has a stronger micro-herd in the soil to break down the cracked corn?

Yes, barring some vegetables which do require different treatment. But on average, treat vegetables like grass, and flowers as something special.

Home Depot and most other big box stores sell hand-held whirlygig spreaders that are great for smaller amounts of material going down. Something like that would be perfect for the Epsom salts.

Side note: if you have a rose, it's probably magnesium deficient in that soil. Take a nice handful of Epsom salt and spread it around the root zone of the bush (which goes wider than the outermost greenery). It'll like that. You'll notice more blossoms that don't die due to blossom end rot, better color, and stronger growth. This is another proof that not all plants react the same way to the same soil. :-)

April first is great for your cracked corn, which can be applied at any point in this schedule. None of the commonly-discussed organic feedings (and very few of any kind of organic overall) will impact anything I'm putting down.

Synthetic feeding has to be adjusted to not be too close to the Ca, K, or Mg applications as it'll tend to be less effective if applied at that time. But the vast majority of organics are A-OK at any time and may actually help the resources bond to the soil.

As usual, I kind of didn't answer the question because I made an assumption that you knew something. Which the question clearly indicates that you don't...sorry.

Your microherd will come up to speed on any organic you give it, whether that's Milo or cracked corn. Not to mention that different members of the microherd favor different feedings, and Milo and cracked corn are very, very different.

Milo doesn't contain a lot of highly durable organic molecules like lignin and cellulose, although it does have some. Cracked corn has tons of these and far lower levels of protein. While bacterial populations are pretty flexible, the same species are not likely to want to digest both (at first, anyway, although the situation is more complex than this).

So six on one, half dozen on the other. I'd probably start with the cracked corn to get it down, and go with Milo thereafter. Maybe some soybean meal in there if I could get my hands on it (it's easy around my place, but maybe not for you).

For that reason, many organic folks recommend mixing things up at least once a year. In my case, soybean meal is the heavy-hitter, with cracked corn once a year, and Milo here and there when I'm in the mood. It helps maintain a diverse microherd, and the parts that aren't getting fed (or don't like the current temperature or moisture level) will happily spore up and wait for better days.

That's good to know about the roses! It's really interesting to see how some have different needs. The wife and I are still deciding which flowers to put down, we have to factor in which ones grow well in this area and it'd be nice to always have at least one species blooming during the spring, summer, and fall.

Yeah based on your previous posts and blogs I'm definitely interested in using soybean meal. I purchased cracked corn and Milorganite this year, but starting next year I'm going to cut back on the Milorganite (mostly for cost reasons) and rotate in soybean meal once I find some around here.

Alright well it looks like a got a solid (and busy!) lawn schedule for this season! I'm really excited to seeing how everything turns out! Thanks again!

Now shifting gears, I'm also going to be attacking all of the weeds in the lawn. My current plan is to blanket spray the lawn with 2,4-D (and a non-ionic surfactant mixed in) at the end of April. So for that I believe the gilmour hose-end sprayer will be fine. After 10 days, I'll see if it needs a second spot spray application.

I'm then planning on following it up by spot spraying with CCO. Are those spray bottles that you find in store good enough, or is it better to buy a larger container and pour it into a hose sprayer or gallon sprayer?

For three season color in a flower garden, consider bulbs for spring (you can span the entire range from ground unfreeze (late March-ish) with crocus to the end of May with English hyacinth and wind flower). Tulips and daffodils can cover the April/May period quite nicely as varieties are available that bloom at various times. Oriental lily is a nice accent, but only blooms once in July or August depending on the variety.

May to October, plan on some annuals. Marigold, zinnia, and dahlia are all reliable bloomers throughout the period, although dahlia tend toward a later start and stronger blossom at the end of the season while the other two are stronger earlier and mid-season.

Fall crocus can round out the October/November garden, as can chrysanthemum.

Small hollies, like Soft Touch, can provide some winter interest and they look great even in February (when not snow-covered!)

re: the spraying, a spray bottle from the store is just fine! I tend to recycle household spray bottles for these purposes, labeling with masking tape and a Sharpie.

Wow that's exactly for a sort of breakdown we were looking for, thanks for the tips!

Final question (though the more I keep reading the more ideas I keep thinking about!) and this is in regards to overseeding.

Last year when we moved in I threw in a mix of KBG and TTTF pretty late in September (yeah I really didn't know anything back then). Some germinated, though the lawn is not completely dense. I understand that the KBG won't really spring into action and spread for awhile so I'm thinking about overseeding this fall. So I have yet to see what the new grass will look like once fully matured.

At first I was thinking of doing a proper overseeding this August with an elite KBG and TTTF mix. However, I've read that it's not worth doing an overseed with elite KBG and if someone were to go with an elite KBG they should just do a complete reno.

I'm not really sure if I'm up for a complete reno, unless the overseed this year still won't make my lawn look nice. On the other hand, I could also increase the density by doing an overseed with only TTTF.

So basically I'm trying to weigh out the pros and cons:

-Overseed with an elite KBG/TTTF mix

-Overseed with just TTTF

-Complete reno and overseed with either a pure KBG blend, elite KBG/TTTF mix, or pure TTTF. If I went this route I would just do a complete reno in the front yard as it's only ~750 sqft., gets sun almost all day as it faces south, and is what everyone would get to see from the road. I'd be fine keeping the the KBG/TTTF mix in the backyard as long as it would still look reasonable.

Overseeding with elite KBG is probably not going to give you great results as the growth habit and color are completely different from standard KBG. Generally that's an exercise in futility and, eventually, renovation.

Overseeding with more standard KBG and/or TTTF mix tends to go much better. The growth rates are closer (but by no means perfectly matched), color is nearly the same, and the habits are identical. The problem arises in that you have to water for the seed, not the existing lawn, so fungal diseases can run rampant. Fortunately, they usually don't in late summer and very early fall.

Renovation isn't difficult, but can be a lot more fraught with terror since you're starting from a clear field. Watering is the same as when overseeding, and you don't need to worry about any existing lawn.

Really, it depends. If you're mostly happy with your existing lawn, overseed with the same stuff.

If you're unhappy with it due to patchiness, the grass is not at fault. Balance the soil, use proper watering and mowing techniques, and overseed. People have absolutely lovely off-the-shelf lawns.

If you're unhappy with it due to growth rate, growth habit, or color, a renovation is in order. This was the place where I stood; the color wasn't what I wanted, it always looked shaggy, and density was not up to snuff. I knew the soil was balanced perfectly, however, so it was definitely the grass, not the soil.

In your case? I think I'd ride it this year, make the soil changes, and see how things go. Well-fed bluegrass spreads like mad, so feed the lawn monthly with 7.5 pounds of protein in organic form (or 1 pound nitrogen in synthetic form, same thing). Wait and see where you are post-greenup next spring and then decide.

Expanding on that last point, 7.5 pounds of protein requires knowing the protein amounts in each type of feed. Too difficult. A good rule of thumb is that you get this in:

15 pounds per thousand square feet of soybean meal -or-

15 pounds per thousand square feet of cottonseed meal -or-

20 pounds per thousand square feet of Milorganite -or-

67 pounds per thousand square feet of cracked corn or corn meal -or-

100 pounds per thousand square feet of oat hulls or rice hulls.

Yeah that's a good point. I'll focus mainly on the soil this year and see how everything looks afterwards. Also thanks for the breakdown of all the nitrogen for different feeds, I've seen them all at different points at some time or another, but it's nice to have them all in one place!

You mentioned applying a starter fertilizer each month for the flower garden to help sustain a higher phosphate. Do you recommend any one in particular? Many of the starter fertilizers also have nitrogen, is that ok to be adding that much nitrogen each month? Or should I look for fertilizers that are lower in nitrogen?

I also found this and was wondering if it, or anything like it, would be any good? It's a liquid so I'm not sure what the best way would be to apply it, but it's 4-15-12.

Get the cheapest granular starter off the shelf--that'll probably be Lesco, but might be another brand. Numbers of 20-27-5 or 18-24-6 or the like are all in perfect range. Granular is easy to apply and always cheaper per pound.

The nitrogen for the flower bed is also required, and flowering plants eat like pigs. I average 1.5 pounds of nitrogen per thousand square feet per month in the gardens, with 1 pound in Milorganite dropped monthly and another half pound via Miracle Gro (more accurately, a cheaper generic) metered in weekly.

You've seen my gardens. They're packed, and I'm intolerant of plants that don't bloom every single second of the growing season (I give my large dahlia a break, but once in bloom they'd better stay there until they freeze). For thinner plantings, or where rest periods of no blooms are tolerable, lower levels of nitrogen and phosphorus are just fine.

While you can go overboard with the nitrogen (and phosphorus, for that matter), 1 to 1.5 pounds of N per thousand square feet per month isn't overboard when most of that is delivered organically.

Don't try this in your vegetable garden, where too much N will give you weak, watery growth that has no flavor. Follow the recommended schedules for what you're growing there, particularly for things like tomatoes. You can end up with a gorgeous tomato bush that has very few tomatoes because the bush is so happy it doesn't feel much need to reproduce.

I did see the Lesco 18-24-6, so I can definitely grab that.

So should I use the Lesco each month and apply at a rate of 4 lbs/1000sqft in order to hit the phosphorus requirement and supplement with Milorganite or a Miracle Grow generic to reach 1 to 1.5 pounds of nitrogen?

Or do I apply enough Lesco for 1 to 1.5 pounds of nitrogen per month and that should supply enough phosphorus for the month?

Sorry I feel like I may be making it more complicated, but I'm not sure what would be more important.

This is sort of an odd period for your (new) flower garden. Target phosphorus the first year, so 4 pounds per thousand square feet--which will deliver 0.72 pounds of nitrogen. Synthetic, in this case, but that's fine.

That'll deliver 1 pound of phosphorus, about six times the actual plant requirement. The rest goes into soil storage and bonds to the soil particles for later release.

You can always fill in with Milorganite, and the organic nitrogen and organics in the Milo will give the soil a boost as well. 6 pounds per thousand square feet of Milo per month will bring the nitrogen levels to 1.0 or near enough.

Post this year, you can discontinue the starter as the soil bank of P will be sufficient. Although if you're as particular as I am, a soil test would be in order.

Phosphorus is an oddball element in the soil. Binding is extremely strong, to the point that only parts per billion are available in the soil solution at any one time. Consequently, it tends to stay put, and wash out only very slowly.

Our job is to make sure that soil levels are high enough that enough is in soil solution to keep the plants happy one hundred percent of the time.

Availability is also a function of soil pH, with P's best availability being around 6.5 (and rapidly falling off above and below that). Fortunately, optimal garden pH for most flowers is 6 to 7, with 6.5 being very nice for most flowering plants (with the exception of azaleas and rhododendron and the like, although I have a rodie that's adjusted to 6.5, stays dark green, and blooms beautifully so it can be done).

While the chemistry is complex, P adjustment is simple. And once settled into place, it won't change quickly even in a very sandy soil. Really, it's the easiest of the resources to deal with in terms of adjustment.

Ok thanks! I would've guessed that phosphorus behaved like nitrogen and would quickly deplete.

I picked up the Lesco starter fertilizer, borax, and epsom salt today. Looking forward to the snow melting so I can finally get out there and start working on the lawn!

I was curious about the other trace elements. So I'll be increasing the boron, the iron is fine, the copper is a little too high, and you said the aluminum wouldn't be a problem. But what about the manganese and zinc? How do they factor into the lawn?

Both your Mn and Zn are fine for lawns and gardens. Manganese gets used by fruits to develop and those that are deficient are rather distasteful looking. Mn also helps with photosynthesis, exchange of gasses to the air, and absorbing nitrogen. Only very small amounts are required. Magnesium and iron are antagonists--high Mn blocks Fe uptake, and vice-versa.

Oh, yeah, that's another thing. I have to balance antagonists against each other so one doesn't dominate. Sometimes you might see me overdo a second (or even third or fourth) resource somewhat to counterbalance an excess of another that's an antagonist to it or them.

Zinc gets used in photosynthesis, sugar production, stalk and seed production, cold tolerance, and lots of enzymes. Low amounts are required, however. Zinc and manganese are antangonists, as are zinc and copper. But zinc and magnesium are friends and higher levels of magnesium increase zinc absorption rates.

In my personal case here, this used to be corn field and very clearly the farmer used a very high manganese fertilizer. Levels are through the roof. I've increased levels of other micro-elements to compensate and everybody's perfectly happy.

Thanks I really appreciate the explanations and reasonings.

I did catch a very minor slip, Manganese is Mn and Magnesium is Mg. Sorry, couldn't resist!

Would this week (once all of the snow has completely melted) be a good time to lay down a pre-m? Also when should I be planning on the first mow? I know it should be lower than normal (~2.5") in order to stimulate growth.

If the soil's unfrozen (mine isn't), you can apply your pre-m. Although it's not strictly necessary until the forsythia bloom; before that, the temperature is too low for seeds to sprout.

First mow for me is once the snow is gone, the soil is no longer soggy, and the frost line has completely disappeared. This year, probably early April. In my case, I just knock off the damaged tips from winter and it seriously improves the look.

It doesn't really stimulate growth--if anything, it damages the grass when it's not quite growing yet, and slows it down. But it also doesn't make a significant difference in green-up, so I do it anyway.

My soil isn't completely unfrozen yet, so I'll wait a week or two.

I guess that's one of those myths that people, and websites, just throw around. If you think about it, it doesn't make sense that cutting the grass would speed its growth when it's just waking up from the winter... oh well!

Just curious (mostly for next year) but if I don't purchase the moss control what are the typical recommendations for potassium sulfate? It's probably more concentrated so would less need to be applied?

Kettle of fish, whole other one, opening of. :-)

In the case of your moss killer, I was working from the assumption (possibly not correct but harmless to make) that it's using potassium chloride. Because that's harsh, I was targeting half a pound of potash equivalent per application, or so. Since your levels aren't that far off, it's not necessary to slam the soil.

With potassium sulfate, I could have you toss around a lot more even though it contains more equivalent potash per pound. Although I probably wouldn't do that since I don't want to overdo the potassium in the top layer all at once, and it takes a while to perk down. I would, however, have had you perform the application much more often as 117 pounds per acre is a fair amount to try to apply.

With potassium sulfate, I could do that in a single year. With potassium chloride, two.

Next year, calcium and magnesium will be in a much better position, so potassium applications will become more prevalent.

At that point, I'd advise potassium sulfate as it'll be the last major resource we'll need to adjust. But there's no need to make you go buy everything at once.

Although I'll advise you to save your box of 20 Mule Team Borax. You're going to need more next year...

Hmm, I can't tell from the product label what type of potassium they're using. They don't seem to mention it.

Don't worry, I definitely won't get rid of anything. I had a feeling I wouldn't be able to elevate everything all in one season!

After doing some research it seems that the moss control doesn't contain any potassium. What would be your recommendations for this year if I were to purchase this potassium sulfate?

You're right, it doesn't seem to contain potassium--but does have plenty of iron, so you can apply it at the recommended rate for a nice lawn green-up (and to kill moss, of course). Don't apply this within 2 weeks and 1 good rainfall of calcium, magnesium, or potassium. It'll bind up.

Even though a much more potent potassium source (50%), you can apply this at the same 3 pounds per thousand I recommended using the moss killer. That'll be 1.50 pounds of potash equivalent, or about 1.25 pounds of elemental potassium per application.

Grasses consume about 2 pounds of potash per year, but you put most of that back when you mulch mow. This'll help build soil levels very nicely.

Sounds good! Ok so I'll be sure to wait 2 weeds between the potassium and Mag-I-Cal/Epsom Salt applications. What would be the best way to apply the potassium sulfate?

I'm using Milorganite as a vehicle for the Borax and Epsom salt (which are also being applied on the same day as the Mag-I-Cal). But I don't plan on feeding the lawn with Milorganite during the recommended times recommended for the potassium.

Actually, don't apply the moss killer near the Ca, K, or Mg. Really, the only problem with doing so with the latter three is that they'll compete for binding points in the soil with each other (and the calcium will win, with the magnesium in second place).

Strangely, Milo plays well with other applications (or not so strangely, most of the iron there is organically bound and doesn't compete very much, if at all).

A handheld whirlygig spreader (Home Depot, Lowe's, most other big box stores) would be best for application here. This amount is too small for a standard spreader, and too large to mix with a carrier.

Ok so I shouldn't apply the moss control within 2 weeks from Ca, K, or Mg, but can I apply calcium (from Mag-I-Cal) and potassium sulfate on the same day?

Theoretically? It won't chemically react. In real life? The calcium will out-compete the K in finding soil attachment points while a higher percentage of K washes out than normally would. That's why I separate things by 2 weeks in the schedule.

Also, if you don't mind double checking everything and seeing if I've made any mistakes, but this is what I have for this season's plan:

Every month from April-September: Apply Lesco 18-24-12 starter (4 lbs/k) to the flower garden.

April 4: Apply cracked corn (20 lbs/k), Mag-I-Cal (5 lbs/k), Epsom Salt (2 lbs/k), and Potassium Sulfate (3 lbs/k). Apply pre-emergent to the lawn. Condition soil with shampoo (3 oz/k).

-1st mow of the lawn sometime in between?

April 18: Apply moss control (bag rate). Condition soil with shampoo (3 oz/k).

April 23: Spray entire lawn with 2,4-D + non-ionic surfactant.

May 3: Apply Milorganite (bag rate), Epsom Salt (2 lbs/k), and Borax (4 Tbsp/k). Reapply 2,4-D.

May 11: Apply Milorganite (bag rate). Spot spray Chickweed, Clover, Oxalis.

May 24: Spot spray Chickweed, Clover, Oxalis.

June 5: Apply Epsom Salt (1 lb/k).

June 15: Apply Potassium Sulfate (3 lbs/k). *You previously had listed moss control here. However, since we found out that the moss control doesn't contain potassium should I still use it here. Or would it be better to save the iron for later, such as after the overseeding?*

August 1: Use Round Up for necessary areas.

August 7: Reapply Round Up where needed.

August 14: Scalp lawn and remove all possible dead vegetation. Spread seed, cover with compost or peat moss (not sure?) and apply Milorganite (bag rate).

August 21: Apply more seed by hands in patchy areas.

September 5: First mow of new seedlings. Apply Lesco 18-24-12 starter fertilizer (should I use bag rate or aim to hit 1 lb of Nitrogen/k?). Apply Milorganite (bag rate).

October 3: Apply Milorganite (bag rate), Mag-I-Cal (4 lbs/k).

October 15: Apply Epsom Salt (2 lbs/k).

October 20: Apply Milorganite (bag rate) and Borax (4 Tbsp/k).

Mid November: Apply winterizer fertilizer or urea (1 to 1.5 lbs N/k).

Just saw your previous reply so I guess I'd move the first application of potassium sulfate to a later date so I'm not putting it down at the same time as the Mag-I-Cal or the moss control. Thanks!

I had 'em scheduled for April first and April 15th, but if the dates have to shift around a bit, no matter. Divide out the magnesium (Epsom salts) from the others as well--same issue. Calcium binds strongly, magnesium more weakly, potassium quite weakly. In any contest involving the three, calcium wins.

First mow happens whenever it happens, so no matter if it falls on the same day as an application. Same with the shampoo, it won't interact significantly--although sodium binds even more strongly than calcium, there's no great amount going down (quite small, actually) and the sodium ion isn't the one we're worried about.

You can drop the moss killer at any time to kill moss or green the lawn, but again, try to move it away from any other application. Other than that, no limitations. Iron, yet another positively charged ion, competes with everything else.

Go with bag rate on the starter at seeding time. Sprouts don't require feeding until they're one month old or so anyway, the seed contains everything they require for their first month of life. You'll pick up their first required N feeding with the Milorganite in early October, which will slowly release over three or more months of decent weather (and stop in cold weather).

Thanks morpheus! Yeah I had to push them back since I wouldn't be able to get those down during the week.

My only concern with applying starter at seeding time was that the existing grass (in the areas that I'm overseeding) would grow faster than the new seedlings and outcompete them. Would waiting until the first mow of the seedlings to apply synthetic starter be too much for them at that time?

Yeah, I never check the calendar when doing this, I just use the first and fifteenth as a holder for "first weekend of the month" and "third weekend." Ish. Give or take. Plus or minus. Around that. Actual dates aren't all that important as long as apps don't wander so much they end up going down in the middle of July. The grass is already stressed then, although calcium wouldn't cause much issue.

I have a distinct feeling that your grass will be growing at jig speed once the resources correct. However, sure, meander the starter into October if you like and shift the Milo to September instead. That won't set off severe growth--and yes, the seed does contain enough phosphorus for them to get started.

The young sprouts won't have any issue at all with the starter going down on them at a month old. I'm growing 850 annuals in the cellar and they're regularly getting nitrogen applications at ages of down to one week (while their requirements differ, sensitivities generally don't between monocots and dicots, and N can't leach out from a sealed base container).

You may find your need to overseed has faded a bit by mid-August when the weather starts to turn at night. We'll see.