Calochortus from seed - raised bed planting question
Tue, 22 Oct 2019 21:37:53 PDT
George wrote:

> Will either the odd soil mix, or traces from whatever plants that have
been growing there, make it risky to start calochortus seeds in these beds?

You've gotten a lot of good advice already, so let me just add a couple of
notes on what works for me in San Jose, CA.

For more than a decade I grew Calochortus in 8-inch plastic pots (the ones
that are colored like clay pots). I used a soil mix of 50-50 peat and sand,
supplemented with a complete non-organic fertilizer (I think the organic
stuff encourages rot). That worked well, but I had to repot every three
years or so because the bulbs dove to the bottom of the pot. If they hit
bottom and weren't repotted, they tended to die.

Since then I tried two experiments, both of which have seemed to help. One
experiment was to grow them in tree pots, which are more than a foot tall
(1/3 meter). That helped with the deep-diving issue.

Then I moved a lot of them into a raised bed, with wood sides. The soil in
the bed is about 7-8 inches deep. It's a mix of equal parts sand, pea
gravel, and planting mix. I don't know if the bulbs in that bed are diving
deep, but there's topsoil under the bed, so they have options.

I had good luck with both the tree pots and the raised bed. Last year in the
raised beds I had good bloom from C. venustus, catalinae, weedii,
argillosus, amabilis, uniflorus, and (gasp) some hybrids. Some of those
Calochortus were moved over as bulbs, but many grew directly from seeds I
planted in the beds.

I really like the sound of those beds you described, George. They're nice
and deep, and a good size to raise a ton of bulbs. The only thing that
worries me is that the soil in them sounds pretty rich. If you keep that
existing soil, I'd recommend making sure it's well amended with some
non-organic material so it isn't too rich and has good air porosity. Maybe
add perlite or pumice? Or sand, but make sure it doesn't have a lot of fines
in it. Sandblasting sand works well. Remember that you'll be leaving the
bulbs in the bed for years, so you don't want a ton of organic material that
will break down into dusty goo in a few years.

There was a very accomplished grower near here who grew C. kennedyi in
raised rows, but I don't know if or how he amended that soil (most of the
soil around here is heavy clay). Whatever he did, it was a huge
accomplishment -- kennedyi is a desert species and really sensitive to

As others have said, no water in summer, and water once a week when they're
in growth.

Good luck! Please let us know how they do.

San Jose, CA
(zone 9, min temp 20F / -6C)

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