This year we are growing 4 varieties of broccoli in our trial gardens to see how they compare to one another during the summer months:Green Sprouting Calabrese, Di Ciccio, Purple Peacock and Romanesco.
The focus of this trial is to observe how these varieties perform in the heat of summer. Our summer broccoli trial planting has been under the protection of row cover until recently, speeding up their maturity by a week. So far, the earliest heading broccolis from our trial are Green Sprouting Calabrese and Di Ciccio, maturing at a fast 45-days from transplant. We have yet to harvest Purple Peacock and Romanesco.
Piracicaba is a Seed Library staple variety. We are extremely familiar with the growth habit of this broccoli. We grow it for seed almost every year because we are one of the two producers of seed for it in the US. It comes to us from Brazil, was developed as a heat tolerant broccoli, and that's why we love it. It rewards us with crunchy, sweet side shoots all season long, when other broccolis peter out before the end of the season. Our main question of the moment is, is there another variety that compares to Piracicaba?
From the first harvest we have found that Green Sprouting is quite similar to Piracicaba. It does not produce a dense central head, but instead produces one main branching head with long stems and large buds. From the plant structure, it seems it will produce lots of side shoots as the season progresses.
Di Ciccio is a classic heirloom heading broccoli. It produces a smaller, tighter central head on shorter stalks with shorter florets as the side shoots.
Purple Peacock's growth has been slow, but the plants are healthy. Romanesco is a long season type, and is not expected to mature for another 4-5 weeks. We are interested in how the heat affects these varieties' ability to produce in the north-eastern climate, since they need to be planted during the hottest part of the year in order to mature.
Harvest question of the week: When do I harvest my broccoli?
If your broccoli has yellow flowers opening up all around, the prime harvest window for that head has passed. When we eat broccoli, we are eating clusters of flower buds, so the key is to harvest the heads before the buds open. When the head is just forming, the buds are generally small, pale green and very tight, see below:
In 5-7 days time, the buds will mature a bit more, swell up, and loosen and the stalk will lengthen a bit, pushing the head up. Once all this occurs, the head is at its optimum harvest stage. After harvesting the initial head, the plant can be left in the ground and will continue to produce side shoots. Side shoots are much smaller than the initial head, so look to the bud size to know when to harvest.
- If your heads are already flowering and you want to harvest broccoli from those plants in a couple of weeks, cut the flowering head off asap. By doing this you will direct the plant's energy into producing more buds, not opening up more flowers.
- Broccoli likes a lot of fertility, plenty of water and cooler temperatures, which is why your spring plantings might start to look ragged towards August. If this has been your experience, try doing a planting of broccoli for fall harvests. The seeds should be started about 10 weeks before your first fall frost, and transplanted 4-6 weeks later.
Interested in what we are doing at our trial gardens? We sell extra produce from trials at our weekly farm store!