There are many vegetables in the cruciferous family that we can grow in Montana. Kale, cabbage, cauliflower, broccoli, kohlrabi, and Brussels sprouts are some of the more popular ones. (Did you know arugula is also a brassica? Its nickname is rocket because it is quick to bolt in the heat, so remember to plant early and in succession for a longer harvest time.) Brassicas are some of the most nutritious vegetables you can grow. All members of the brassica family have similar nutrient profiles and contain calcium, magnesium, potassium, phosphorous, beta carotene, folic acid, vitamins C, E, K, and iodine. They have powerful anti-oxidants and they are beneficial eaten raw or cooked.
Here in the harsh climate of Montana, timing is important and the shorter season vegetables and their cultivars will be the most likely to come to full fruition. Most brassicas do best in soil pH of 6.5-7.5, so a little elemental sulfur can be helpful. They prefer firm, very fertile, well-drained soil with plenty of compost and additional food during the growing season. They require full sun, which is at least 5-6 hours of sun a day and do best in soil temperatures of 50-65 degrees. They do not thrive in hot weather and therefore do better on the shoulder seasons. In fact, they not only tolerate light frost but often become sweeter after a little nip of cold. Furthermore, most brassicas need the stimulation of cold weather to form heads; Brussels sprouts in particular need cold to form the sprouts. Seeds are usually planted six weeks before the last frost. Transplants should be set out in the garden in the middle of May. The following Montguide is invaluable for determining the planting time of all veggies. http://msuextension.org/carbon/documents/yggarden.pdf
Working your garden in wet conditions, which we usually have in the spring, is harmful to the texture of your soil, and compaction is difficult to reverse, so it’s best to prepare your beds in fall so you can get into your garden and plant early without causing damage. It’s also best to plant brassicas from transplants that are started indoors, not only to get a jump on the season but to reduce the risk of disease and insect attack. Set your seedlings deep enough to cover the stalk up to the first set of leaves and make sure your hole is deep enough to keep the tap root straight. Press the soil around them gently and water in well. Remember to check your spacing for the different varieties so they don’t grow too close together.
A tip that I have found to be very helpful is the addition of mulch. Using mulch around your plants not only prevents weeds, it also keeps the soil cooler, retains moisture, reduces compaction from the rain, and keeps your plants cleaner. Along with cool soil and lots of nutrients, brassicas need consistent moisture, so remember to water regularly. Eat some of the lower leaves as the plants mature and remove any yellowing lower leaves to provide good air circulation and reduce the risk of fungal disease.
Insects and furry critters can be a real annoyance when growing brassicas. (Think cabbage moth and deer among others!) The least invasive defense against insects is a good squirt of water to the leaves, preferably done in the morning so they have time to dry before nightfall. This will disrupt the life cycle of soft bodied insects without using chemicals. If you are still struggling but don’t want to use chemicals, a floating row cover prevents insect attack and as a bonus keeps the deer and rabbits off too. This is best applied soon after planting to be most effective.
If you grew kale this season, you have probably already been harvesting for a month or more, but if you got a late start like I did, your Brussels sprouts may just be forming. Remember to be patient and keep your brassicas going through our early frosts for a longer, fuller and sweeter harvest! There are so many wonderful varieties of healthy veggies to try; if you didn’t plant any cruciferous vegetables this year, prepare your bed this fall and get ready to enjoy the glorious fruits of your labor next year! Some of the following reference links are live and some are not:
Respectfully submitted by Ann McKean