Hi, Mark. On occasion, I've placed the 5:1:1 mix (when it was completely dry & hydrophobic) in a shallow pan of water overnight. By morning, the top of the soil was moist, so I know it wicks well. Still, I'm told by others with more experience growing in SWCs, that it may not wick fast enough to supply immature plants with water or to keep the fertilizer strip wet. Perhaps JaG or another experienced poster can come along with more help. FWIW - the mix with 2 parts perlite will be a little less efficient in the wicking dept. In a SWC, you might wish to up the peat and add a small amount of vermiculite to the soil. I'm guessing that something like:
7 bark fines
2 peat
1 perlite
1 vermiculite
1 tbsp garden lime/gallon
would probably be a very good mix for SWCs.

For a fertilizer program, I would use something with a 3:1:2 ratio like MG 24-8-16 for the first month after potting, then switch to a 1:2:2 ratio like 5-10-10 or even a 1:1:1 blend such as the 14-14-14 you're using. Please be sure your plants are getting the secondary macronutrients and all the minors. Ca and Mg are particularly important.

Good luck, Mark.

Al

Thanks for the great follow-up, Al.
I'll readjust the mix as described - I'm just storing it in a 28gal container at the moment. I have limited experience with gardening and in particular with fertilizer (I usually go organic but have no objections to the chems in the context of containers). When I hear Miracle-Gro, I think of the blue water stuff - is that what you're suggesting for the first month, or is there a granulated Miracle-Gro that I should mix directly into the container? The 14-14-14 (Osmocote, I think) is coarsely granulated - would I just apply this to the top of the mix?

The homemade SWC I'm using uses the top of the bucket as a mulch (just cut a hole in the lid for the plant), so opening and closing the planter is tricky if you don't want to damage the plant stem. Maybe I should just go with water soluble fertilizer and put it directly into the reservoir? I'll also check out the link to the EB forum provided above.

I promise pics and success/failure story based around this advice!

Thanks,
Mark

Yikes! "I promise pics and success/failure story based around this advice!" really puts me on the spot! Lolol ;o)

I'm pretty sure the soil I suggested will do a very good job, but before you amend your soil, why don't you wait for JaG to stop by & confirm what I said? He really seems to know his way around the SWCs and may offer additional insight. He always offers good insight.

The MG products will either be liquid (12-4-8) or granular soluble (24-8-16) (not mixed into the soil). Dyna-Gro makes a fertilizer I'm really excited about in the same ratio - it's called Foliage-Pro 9-3-6, and it contains the secondary macros and all the minors. It should be a great fertilizer for container plants. The Osmocote 14-14-14 is likely a controlled release and is better incorporated into soils, rather than broadcast. As long as you're diligent about fertilizing, you could skip the Osmocote altogether & stick with the program I outlined, using soluble ferts. It's your call. ;o)

All the best . . .

Al

Mark, the modified mix Al recommends is a good place to start, but are you planning on covering the container and relying upon a strip of fertilizer on the surface to feed the plants?

This is critical because if you will use the cover/fert strip you really need a fast wicking potting mix and this means peat and vermiculite. What I often tell people getting started with Earthboxes where a cover and fertilizer strip will be used is that the system was designed with peat based mixes and it works very well with them so give that a try for a year. It will give you a good frame of reference for tinkering in subsequent years.

Assuming you do not wish to do this then:

I would encourage you to make a mix and set it outside to see if it will keep the surface moist for a couple days before committing. This is if you will use the cover and fertilizer strip. If you won't use either then Al's mix (original or modified) will work fine.

Keep in mind my experience is in Wisconsin, somebody in a hotter/drier/windier climate might need to modify a bit. Even with the cover on, the wind gets under it from the holes we must cut for the plants. This wind may not seem like much, but it can quickly dry the surface.

You really do need to test though, that's the best approach. Just do it outside. I say this because I made the mistake of evaluating how well various materials wicked *inside* (I was going through an endless winter and wanted a gardening 'project'). How something wicks indoors is waaaay different than how it wicks outside due to temp, wind, humidity etc.

Again though, you really only need to modify Al's mix with fast wickers like vermiculite or peat if you want to use the cover and fert strip.

One last tip, if you find that the very surface goes and stays dry, but an inch down it's moist you can simply bury the fertilizer strip an inch under the surface. This gives more latitude in compromising between a coarse mix that drains well and one that can wick fast enough to keep that fert strip working.

Happy growing.

JaG-
Thanks for the response.

I've seen it on this forum and elsewhere, but I frankly don't get the "strip of fertilizer on the top" that I see for "earthbox" style containers - is this just some simplifying technique conceived by the creators of the "real" Earthbox? I assume it's just for annuals - what if you have a multi-year planting and you can't just pop the top off to refresh? I'm hoping to do fig trees in similar 5gal containers - I know that I'll have to repot every few years with fresh mix and potentially not use the partially composted fines, but that's another forum post at some point.

Rather than mucking about with a strip (which might get wet in a heavy rainstorm in a 5gal container that's only 12" wide), why not just rely on slow-release fertilizer at the start and water-soluble MG fertilizer added to the reservoir on an ongoing basis? I do however very much like the idea of using the lid as a mulch for a single-stem plant like a tomato - that really ought to limit evaporation greatly, although I see your point about wind evaporation. I'm planning on using my hot, sun drenched but occasionally windy patio - I'm already figuring out a way to secure the pot to the wall for storms.

I think I'm going to follow Al's "modified" 7:2:1:1 mix and initially fertilize with a soluble 3:1:2 MG and switch to a water soluble 1:2:2 or 1:1:1 and keep the top on permanently. Thus no granular fertilizer at all, unless I should go ahead and use the 14:14:14 Osmocote when initially mixing the soil?

Someone please correct me if I've totally botched this.

Like I said, this forum is great.

The idea behind the fertilizer strip is definitely to make things easier. It's part of the 'method' for the commercial earthboxes. For a short season planting like veggies it can and does work really well.

For what you want to do you are probably better off with your current plans to use CRF mixed in plus a soluble fert.

I don't have any experience with trees in SWCs so can't offer any information there. Overall what you are planning seems very sound though.

Mark,

Last year I had a tomato plant in a 5gallon SWC with a 1:1:1 ratio of bark:peat:turface. Used pine needles as mulch.
At first it did the best compared to an earthbox recommended mix. Great root structure.

But as is got hotter (northern CA), the top 1/3rd of the container kept going hydrophobic (or was dry). That plant, although it had the best roots, did the worst.

I had tested the soil beforehand and it seemed to wick great. Left a pile of it in a wheelbarrow outside and it wicked 2 feet no problem. I guess the hotter summer weather and the fast drinking tomato plant though were too much for it. It might have done better with a plastic sheet mulch right on the top of the soil, but I wanted more chance for air to enter in.

CRFs mixed in the soil work well for me, with some extra seaweed waterings through the year.

This year I went back to my Garden Supply SWCs. They have the lower soil depth, so wicking should be easier. And I'm using (untested) 1 part peat, 1 part lava rocks (just to keep it simple).

I agree for the first time, you probably want to mostly use the earthbox recommended mix and then have 1 or 2 extra planters for soil experiments.

Seeing a great harvest of tomatoes out of a "little" SWC is great and keeps me motivated to replant every year.

Thanks for the insights, emgardner.
In my design I'm using the tops of the white buckets as "mulch" - just cutting a hole for the plant stem. I'm hoping this greatly reduces moisture loss over a typical mulch, but it also makes supplemental top watering more difficult.

I've been reading pretty extensively and have seen several statements to the effect that 5 gallons isn't large enough. Elsewhere I've seen claims that although tomatoes don't grow as large in 5gal containers, multiple 5gal containers are more productive than an equivalent large container. I think the claim was that while a 20gal container yielded more than a 5gal, 4x5gal containers yielded much more than 1x20gal. This is consistent with what I envisioned - in my space where I can probably put in 5x5gals or 2x20gals. With 5x5gals I can have more variety and more tolerance for disease/disasters. We'll see how I do...

The other issue I've seen in my readings is that the 5gal buckets tend to become top-heavy and fall. Since I'm putting the pots against the house wall on the patio, I'm planning to just use some wire between eye bolts above the planters and use wire ties to secure the tomato support to the wire. We'll see how that goes - I'm hoping that proximity to the wall doesn't cause issues with air circulation and disease (although the good thing about SWC is that you don't get your leaves wet when watering).

At Gardener's Supply, one thing I got is the "planter" (#35-901) which looks like the same thing they use for their "tomato success kit" minus the kit. I'm planning to use it for part of my herb garden. As for Brinn's comment above, I wouldn't buy any of their larger "SWC" pots again. They're just a standard pots you could theoretically buy anywhere sent with Gardener's adjustable reservoir (#34-507). Although the pot they sent me was in fact quite nice and not overpriced, I could probably get something on sale locally and just use the adjustable reservoir.

Mark