Extreme Gardening

Extreme Gardening

Creating a new broccoli variety – breeding for organic conditions
Selection at 0.01%

The goal: to create a vigorous open pollinated broccoli variety, developed to thrive under organic conditions and able to survive and produce under substantial weed pressure.
I want a broccoli that can be sown into only moderately fertile ground, out-compete weeds and still produce broccoli

The method:

First, a broad and diverse parent stock. The seed for this project was grown out from seed provided by the Oregon State University plant breeding program. This seed is in the public domain. In 2003, as a part of the Farmer’s Cooperative Genome Project, I grew out about 150 plants from this diverse breeding stock provided by the University. I selected about 25 plants and saved seed, part of which was returned to O.S.U. This seed is a diverse population of open pollinated broccoli varieties that had been mixed and grown together. I had 10 lbs. of this seed left over.

Second, a challenging site for the plants to grow: This ground has a high weed seed load. Last year it was in corn, which left it fairly nutritionally deficient. It was disked in and roto-tilled once. It is anything but a clean seed bed. I created 4 “beds”, 6 feet wide and 200 feet long. I fertilized modestly using 100 lbs. of composted chicken manure and 1 yard of raw llama manure on each 6’ x 200’ bed.

Third, a lot of seed. I broadcast – sowed 2 pounds of broccoli seed (200,000+ seeds) on each 6’ x 200’ bed. I planted 800,000 broccoli seeds. These seeds will ultimately be thinned down to 80 or 100 plants. Seeds will have to be both quite vigorous and also lucky to survive in my plot.

Fourth, a lot of weeding and thinning. What came up, as you might guess, is a thick carpet of broccoli seedlings and weeds. The method for weeding and selection I call “rescue weeding”. I don’t want the plants to have too easy a time. Only enough weeding is done to keep the best plants barely ahead of the weeds. Broccoli are thinned to about a 1” x 1” spacing, picking the best from the clumps. Gradually I thin to about a 2” x 2” spacing. I spend the next months rescuing the plants from being overwhelmed and giving the most vigorous an extra inch of space. I never weed anything thoroughly. I only want to give the plants a boost by lessening the competition a little bit. When I get to the end of the patch it is time or past time to start over at the beginning.

I will thin down to the most crowded stand that the plants have a chance to form heads. The remaining 80,000 or so plants will be allowed to try to form a broccoli head. I will continue to thin aggressively, hopefully harvesting many small broccoli for the farmers market. I will make further selection based on the broccoli head, seeking some uniformity and a nice head, although the head will be small because of crowding. In the end, about 100 or so will be kept and allowed to go to seed.

It might work ... it might not. Meanwhile, right now there are still about a quarter of a million little broccoli plants crying out to be rescued. I had better get back to weeding.
-Jonathan Spero May 1, 2009