Hi, I could have sworn I answered this post alread, but I guess not...
I agree about the peat. I used to use it religiously in every planting I did. Now I hate it exactly because of that repellant action it has when watering. I make and use my own compost out of the usual grass, kitchen scraps, non weedy yard waste, manure/barn waste, shredded leaves. It's great stuff.

If I had to buy some I'd just get some basic compost, nothing fancy- a reliable brand if you can. I wouldn't get anything fancy. Then continue to mulch and dig in more of your own each year and you'll have great soil in no time. The difference in where I've mulched and added compost over the years is astounding.

I already posted a while back about how last year I followed Swan Island's directions "use no compost whatsoever..." and I regretted it so much when they didn't grow that I dug up all those tubers, dug in compost after all and then watched them go to town.

I agree with both of you about the peat but it sure helps with the soil. So here's my solution. I went to the local building suppy store and bought a 50lb bag of vermiculite for $8.00 (they sell it for house foundations) and mix it 1/2 and 1/2 with the peat. Works really well!

And on a side note: I just finished scraping the last remnants out of one 'ready' compost pile. Is it wrong of me to have stood by the cartful of black wonder and smelled a few handfuls? It's just the best! I cannot think of a more refreshing, exhilarating smell that cries "SPRING!" except possible freshly mown grass.

Wow - Willow what a great price for Vermiculite! And I've been buying the skimpy bags at the garden centers for the same price. Thanx for the tip! I love all my fresh compost too - Yesterday I turned 2 big piles and started a new one.
The last 2 I dug in and spread around was a marvelous experience! I bet a health study would show positive benefit form inhaling fresh compost aroma.

Preparing soil today - for planting my *first-ever*
FOUR Dahlia beds - with Tubers sent by Poochella!

This is so exciting. Quite a few are showing sprouts already - so I'm really eager to get 'em in the ground.

I'm mixing soft crumbly peat (NO gukky clumps)
into mixed sterile steer compost today - that looks and feels really good: dark with light texture,
so I couldn't resist mulching a bunch of transplants
with it - so i needed to make even more.

Then will dig that in this week - to new lasagna beds
that were turned under in last few weeks,
after having been covered with cardboard,
coffee-grounds & mounded leaves all winter.

The lasagna soil gets broken up to a crumbly state,
then a spade of fresh home-made compost goes in -
with the steer-peat mix for each wide planting hole - mixed well into the origional average dirt that formerly hosted grass. Then planting time - will be irresistable -

Should I wait for planting till I buy more Perlite - (or that vermiculite) or is the 1/3 peat, 1/3 dirt, with the 2 kinds of compost mix good enough to keep soil both light and free from baking/compacting in summer?

I'm leaning toward adding perlite or vermiculite first -
so tubers can form more easily for sharing.

(In Oregon it gets VERY wet sometimes, and also so HOT that the ground can bake into near concrete...)

Besides STAKES,
Can you think of anything else
that should be added for better bloom,
stronger stems, disease resistance, etc?

For Powdery Mildew prevention - I am considering using an early Comfrey foliar spray. And I've realized realize I've got borage in the garden - not comfrey - and I bet that would work *equally* well - but to my knowledge has not been thru the formal studies. Any opinion/experience?

I'm SO ready to go on this!

I sorted alot of tubers into groups today
and added the individual markers to each set
so none get lost once planted.

I plan to add groups if some mystery glads,
Lucifer Crocosmia,
and Canary Yellow Crocosmia (also from Poochella),
with Liatris (the spiky Purple GayFeather) to the beds
for foliage contrast, near existing Roses and Peonies that have nice bronzy leaves.
I expect to remove lower leaves from most Dahlias - and I don't really want their bare legs to show. So on borders I'll also plant some smaller flowers and add contrasting foliage plants.

Who needs grass in the Front yard anyway?!
Mine will be reduced nearly to just a wide path
for flower-bed access. I'm mulling how to best do the watering - I think by hand, slow with an aerating wand on the hose, so I can watch everything develop and spot weeds before they compete.

Another quick question - I have a free source for
Hemlock Bark Dust, that I'm thinking of using it in front just as an edge between grass and the Flowers. Is this OK?

I assume Hemlock is too acidic to use more widely as mulch. In back it's being used just for soft walking paths in full sun areas where grass does not do well and only weeds (and my cookng Amaranth) tend to flourish.

I look forward to finished planting,
& seeing pix of everyone's gardens!

Thanx so much for sharing info -
I've learned alot already.

Jules, If I were a plant, I'd want to end up in your yard! Your excitement and enthusiasm is clear and contagious.

I haven't had to add perlite or vermiculite per se, have done okay with just compost and (formerly) peat moss added to each dahlia hole. If you have heavy clay soil vermiculite might be a great additive. I throw my clay away into an usused part of the property, but others swear it can be turned into workable soil. (I am unconvinced having hand-chiselled through it with a poker hit with a rock and bending a pitchfork tine trying to get a cut into it- hideous stuff.)

If you have fairly decent soil, I'd just go with compost every year and mulch with more when the plants are up a foot or two. I have only the occasional weed directly around dahlias- whether that's from mulching or not, I don't know. The buttercups on the edge of the garden are a totally different story. Your tubers will form clumps easily enough in decent soil. Your yard will soon be the talk of Portland!

Watch your glads for signs of thrips- nearly invisible black streaks ~1/16 inch long. The first sign is foliage damage, then mis-shaped sad flower stalks. Potential disaster if they get into your dahlias. I still haven't planted my thrippy glads from last year and am thinking of burning them instead. Think I got one or two blooms out of 50 bulbs or corms, whatever they are. The pits.

I love watering by hand (please remind me of this in late July and August) It gives you a chance to see how the plants are doing, pluck a stray weed and disbud the dahlias as you go. I will sing a different tune if I ever have more than 150 plants, however. I think I sang that different tune last summer.

Good luck with your garden ventures PDX Jules.