Planting Fall Broccoli in Oklahoma
A while back, someone asked on the carrots thread about tips for planting fall broccoli. Here's a few:
1. Start your own seeds indoors and then transplant. Because broccoli grows relatively fast, you can start the seed only 2 or 3 weeks before your intended transplant date.
In winter, I like to transplant out plants that have 3 to 5 leaves and in the cooler winter conditions, that means starting seed 3 to 5 weeks before transplant date. I find the seedlings grow faster in summer, hence starting them only 2 or 3 weeks before I want to plant them in the ground.
2. As soon as the seeds germinate, I move them to the front porch so they get morning sun and afternoon sun. This cuts down on the need to spend a week hardening them off if they're grown entirely indoors. However, if you work and are away from home all day, it may be more productive to raise them to the three-leaf stage indoors and then harden them off. One issue with starting seedlings in flats at this time of year is that they may need to be watered several times a day if outdoors, particularly if outdoors in full sun.
3. Understand that broccoli is a biennial, so any extreme stress can cause it to form button heads (these literally are broccoli heads that are roughly from button-sized to quarter-sized) which means you won't get much to eat. So, take extra care to make sure your tiny seedlings don't get root bound and don't get excessively hot or dry or malnourished.
4. Why do we avoid store-bought transplants? Back when I did buy store-bought transplants, I often found they were root-bound and stressed. Also, the size of the main stem often was too large for a healthy transplant and already was becoming woody while still in the 6-packs, which is not a good thing because it tends to mean the plant is too old or rootbound and growth has stopped. Often store-bought transplants of broccoli have been on the greenhouse or store shelves too long and the plants are older than they seem, increasing the chance that they are going to cause you the kinds of problems mentioned in 3 above.
5. Can they handle the heat? Yes, they can. The key is that they need consistent moisture. Dry soil is much harder on them than the heat itself. If you've never used drip irrigation or soaker hoses, this is the perfect time to try them and the broccoli will appreciate it.
6. Why plant them in mid-summer? Broccoli tolerates some cold, but prolonged exposure to cold temperatures below the mid-20s often causes buttonheads. Your broccoli plants will be happiest and will produce best when they are growing in temperatures that range roughly from the 40s at night to the 70s during the day. Thus, we must plant when it is insanely hot in order to have our broccoli plants about ready to produce (in terms of DTMs) when temperatures reach that range.
7. Pest problems usually are much lower on fall broccoli than on spring broccoli. Now, that statement applies to a so-called typical year, and if any of you know exactly what is a typical year in Oklahoma, please feel free to enlighten the rest of us. In most years, the imported cabbage worms and cabbage loopers are much less of a problem on cole family crops in late summer/fall than they are in spring/early summer. However, I have noticed in drought years that the pests often remain more of a problem on fall broccoli than they no in a so-called 'normal' year. I have, in fact, seen the dreaded checkered whites flying around in my yard almost every day his summer. They must be living on weeds that they like because there's no cole crops in my garden. Most years you don't have to cover fall broccoli with floating row cover or spray it with Bt, but this drought summer might be an exception.
8. If you're new to growing broccoli, remember that after you harvest the main head, the plant often will produce side shoots. You also can prolong your harvest by planting 2 to 4 varieties that have different DTMs for a more continual harvest.
9. For both spring and fall broccoli, I like to plant where the plants get morning sun and afternoon shade. This is not necessary, but I find it helps the plant during hot weather. If your garden doesn't have than kind of shade, you can use shade cloth, old sheets, or even newspaper or cardboard to temporarily shade young broccoli plants. To use newspaper, I put tomato cages around the plants, or in a row beside them and use clothespins to clip the newspaper to the cages to form sort of an awning that shades them from the worst heat of the day. With cardboard, I use large sheets of it propped against wooden grade stakes hammered into the ground. I lean the cardboard against the stake. If your garden is in a windy exposure, you can use large stones or bricks laid against the cardboard to keep it from going airborne. The plants benefit from shade more in August than later in fall, so that's one argument for planting them in full sun, but using shading to help them survive summer long enough to make it to fall, when you can remove the shading. I wouldn't put them in full shade, though, as they need some direct sun in order to grow.
If those of you who were looking for broccoli tips have any more questions, feel free to ask. I know there's several of us here who grow broccoli in fall, at least in good years when the drought levels are not insane.