‘making more plants’ with ken druse (and how to avoid damping off)
I AM SOWING MY FIRST SEEDS other than onions about now—Brussels sprouts and broccoli today, with tomato-sowing time just ahead here at mid-month—with a comforting, luscious copy of Ken Druse’s 2012 paperback edition of “Making More Plants” by my side. I’m sharing some of Ken’s advice on preventing that most dreaded of seed-starting mishaps: the fungal killer called damping off.
Like all of Ken’s 18 books (!!!), “Making More Plants: The Science, Art and Joy of Propagation” is rich in instruction, but also visually arresting, since he’s an award-winning photographer, too. It covers the botany of propagation—the why’s behind how you can make more plants of a particular species sexually or asexually or both—because as Ken says:
“It is not essential to learn about botany to garden well; it’s inevitable.”
Then in words and intimate pictures he covers virtually every tactic for doing so, from seed-sowing to leaf and root cuttings, to layering, grafting, division and more. The photos are so beautiful, and Ken’s obvious enthusiasm so evident on every page, that I want to try everything. (Just what I need: more plants!)
But trying to be timely and topical, I asked Ken for his most popular seed-starting tip—which he said without hesitation was how to prevent damping off. It’s all in the poultry grit, you see:
how ken druse prevents damping off
(By Ken Druse)
A LOT OF PEOPLE have trouble with damping off, the fungal diseases that attack seedlings. I do not use potentially toxic fungicide. Instead (like alpine plant people do), I fill pots to the brim with sowing medium (recipe below), tamp that down, sow and sprinkle on a little more medium to cover the seeds followed by a thin layer of fine chicken grit or very coarse sand.
Flaked granite chicken grit (“starter” is the finest grade for small seeds) is available at all agricultural supply stores. It is inexpensive but comes in large and heavy bags. Perhaps you can get some friends to share the lifetime supply you’ll get for about ten bucks, but it can also be used as a potting soil amendment for improving drainage. (I used to be able to substitute parakeet gravel, but lately the product seems to have changed and is no longer simply very coarse sand.)
Filling the pots to the brim reduces the area where air might be trapped along with pathogens. The inert grit is an inhospitable material for fungal growth.
I sow most seeds in very clean, 3.5-inch square pots, from 6 to 60 seeds or more, depending on their size. Fewer seeds if big (squash, for instance), more if small (flowering tobacco). Cover the seeds to a depth equal to their thickness (Nicotiana and seeds that need light to germinate get no extra medium).
Recipe: The medium can be a store-bought, peat-based sowing preparation with the addition of grit or perlite to “open it up” a bit–improve the drainage–since regular sowing media tend to get waterlogged. The medium can be around 20% grit or perlite.
“I usually use sifted coir (coconut hull fiber– available as compressed blocks from mail-order garden suppliers and better garden centers) and perlite, or sifted compost with perlite. I place compost or any questionably clean seed-sowing medium in a store-bought roasting bag in a microwave-safe pan and zap it for approximately 10 minutes on full power until an instant-read thermometer plunged into the center registers around 160 degrees F.
Be careful opening the bag in case there might be a cloud of steam.
After sowing, I water the seeds from the bottom by placing their pots in a shallow pan of water until the grit on top changes color–from white to gray. The pots may not need watering again until after they are up and growing.
where to find ken and his books
- Visit Ken’s website, Ken Druse [dot] com
- Order “Making More Plants” now
- Listen to/subscribe to Ken’s weekly “Real Dirt” podcast
how to win ‘making more plants’
TO ENTER TO WIN A COPY of “Making More Plants,” simply comment below, answering the question: What seeds are you sowing indoors (or out) this spring, and what seeds have given you the hardest time in the past? [Note: the giveaway is complete, but comments are always welcome.]
I know–some of you are shy (or aren’t sowing anything!) so in those cases just say, “Count me in!” and you’ll be entered for the random drawing. My answer: Besides the Brussels sprouts I mentioned, I’m going to give broccoli another try this year–those will be among my first indoors sowings.
I’ll pick a winner after entries close at midnight Sunday, April 8, 2012. Good luck to all–with the contest, and with this year’s seed-sowing adventures.
(Photos courtesy of Ken Druse, from “Making More Plants.”)