- Category: Blog
- Published: Wednesday, 20 March 2019 13:41
- Written by Jack Wilbur
- Hits: 674
Spring is here and many of us are stating to think about our yards and gardens. If you can’t wait to start planting your vegetable garden, here are some guidelines about when to plant certain crops.
Generally, when it comes to their sensitivity to cold temperatures, vegetables fit into one of four groups: very cold hardy, semi-hardy, semi-tender and very tender.
Very hardy = Tolerate temperatures below 28 degrees Fahrenheit
Semi-hardy = 28-32 degrees
Semi-tender = Temperatures down to 32 or just above
Very tender = Don’t even show them a picture of freezing temperatures.
Since most of Utah will still see many more nights with overnight temperatures in the 20s, today’s post will focus on the very hardy and semi-hardy crops for your vegetable garden. A later spring post will focus on the tender plants.
Very cold hardy veggies and herbs:
Garlic: The green stems of garlic are among the first things to emerge in late winter or early spring, as you can see in the photo to the left. Heavy spring snow and very cold temperatures do not impact the bulbs underground. The cold only slows growth above ground. The bad news about garlic? In order to have nice large bulbs later this summer you should have planted last fall.
Arugula: This peppery green has a fun name to say and it is super cold hardy. A member of the mustard family, arugula will over winter in some places, but it certainly can be planted in spring as soon as the ground is workable. Like most cold hardy greens, arugula will bolt, or go to seed when it gets hot, but unlike many of the others, it will grow well in heat if planted later when it’s hot.
Beets: Like arugula, beets do well in cold or warm conditions. Staggered planting every couple of weeks throughout the growing season will ensure a consistent supply of these sweet treats. Bonus: young beet greens can be harvested when very young to be used in salad or when they are a little larger they are great cooked.
Peas: As soon as you can work the ground you can plant peas. One drawback to planting when the ground is too cold is the number of days until germination goes way up. If your soil temperature is below 40 degrees and you expect a lot of cold, wet weather it may take a few weeks for your peas to germinate. Pea seeds can rot in the ground, but that usually isn’t an issue here in the arid West.
Cabbage: Cabbage can withstand temperature down to 15-20 degrees. Plant when ready.
Carrots: Carrots are also great in cold temperatures, but they don’t germinate well in very cold soils. Many gardeners will plant in fall for a spring crop and cover the crops with row covers, straw or other mulch to overwinter the plants. For best results in spring, hold off planting until the soil warms to around 45-50. Even then it can take 2-3 weeks for carrots to germinate.
Cauliflower: Cauliflower can handle temperatures down to 10. Plant as soon as you can work the ground.
Collards: Collards are even more cold hardy than cauliflower and fairly heat tolerant. If you have never grown them they are pretty easy to grow and very prolific. Give this Southern treat a try.
Onions and green onions: Onions and green onions are another crop that can be planted in the fall and overwintered for an early spring harvest, or planted in spring as early as the ground can be worked. Green onions are a shorter duration crop. Consider stagger planting them well into late spring and start again in late summer for a fall crop.
Parsnips: These root vegetables are very cold hardy and they take a long time to grow. Get them in as soon as possible.
Radishes: Radishes are wonderful in spring salads and one of the shortest duration crops around, often 25-30 days. Plant early and often if you like these spicy orbs. If a traditional cherry belle type or red round radish is too hot for your tastes, try a variety like French Breakfast. They are cylinder shape, red and white in color and very mild.
Spinach: Plant as early as you can. Most spinach varieties do not do well in heat.
Swiss Chard: Swiss chard is another crop that likes cold and tolerates heat.
Kale: Kale does very well in temperatures down to about 20 degrees and, like Swiss chard and collards, will tolerate heat.
Semi-cold hardy crops (28-32 degrees):
Lettuce: Whether you prefer a spring mix type of baby loose leaf greens or head lettuces are more your speed, plant when temperatures in your area average 28 and above overnight.
Broccoli: Broccoli is good down to 28 but it is a gamble below that temperature. You may want to wait a while, but if you live in the lower elevation valleys where it tends to get fairly hot by mid-June, don’t wait too long to plant. Broccoli will bolt or get bitter tasting if it gets too hot for too long before harvest.
Celery: Celery only tolerates light frost. Wait a while to plant, but it is worth the wait. Utah has a great climate for these green stalks.
Rutabagas: This old time crop is making a comeback. Like many of the cold season crops, its taste actually improves when exposed to light frost, but it doesn’t abide heavy frosts.
Turnips: They could technically be in either the very cold hardy category or this one. The thing about turnips is they taste better when they finish maturing in warm weather, so think of them as semi-cold hardy and hold off just a while before planting.