In a previous article titled Growing Winter Veggies, we noted that you could extend your enjoyment of gardening into the winter months with a winter garden consisting of hardy vegetables that can withstand cold winter conditions.
In this article, we will discuss when to plant the veggies in regions throughout the U.S. using the USDA Plant Hardiness Zone map.
The secret of growing a flourishing garden in winter is to plant on a schedule that will give the crops plenty of time to establish before the first winter frost sets in. Knowing the approximate maturity lengths for different cold-hardy plants is more than essential.
Planting By Zone
I have some bad news for gardeners who reside in Alaska and the most northern states in the continental U.S. Growing veggies during winter in these regions is difficult at best. That’s because the sunlight in winter is marginal and the temperatures can drop to -40°F or below. These conditions are just too harsh for growing a garden through the winter months. However, you can use a combination of the protective devices discussed in the previous article to extend your gardening into fall. An indoor container garden under lights would work best if you want the advantage of having fresh greens on your table through winter.
The region of the country that has the harshest winter conditions in which cold-hardy crops will thrive is in Zone 4, which includes states in the Rocky Mountains, plains and the northeast region known as New England. Although this section receives heavy snow and freezing temperatures that can slip as low as -35°F you can grow cold-hardy crops as long as they are guarded against the snow, wind, and cold by protection devices discussed in the previous article on this subject. However, the devices must be well built. Hooper tunnels would probably not suffice because they can collapse and therefore crush plants. It is suggested that you regularly sweep snow off the device you use to permit light in. If temperatures are forecasted to drop sharply after a snowfall and the protective device can take the snow load, it is suggested that you leave the snow alone for a few days. The snow cover will insulate the crops. They’ll do fine without sunlight for a few days.
It is common for the first frost to appear on September 15 in Zone 4. So here is the planting schedule:
• Slowly maturing cold-hardy crops should be planted around June 1.
• Middle maturing cold-hardy crops should be planted around July 1.
• Quickly maturing cold-hardy crops should be planted around August 1.
A combination of mulch and cold frame placed under a well-supported hoop tunnel or inside an unheated greenhouse should sufficiently protect the veggies. It is suggested that you drape an insulated blanket over the device or add electric lights if necessary.
Zones 5, 6, and 7 runs across the middle sections of the country. They can experience heavy snow and temperatures can drop to about 29°F to negative 16°F.
The first frost typically collides with Zones 5, 6, and 7 around October 15.
• Slowly maturing cold-hardy crops should be planted around July 1.
• Middle maturing cold-hardy crops should be installed by August 1.
• Quickly maturing cold-hardy crops should be planted by September 1.
Mulch and a cold frame or row cover placed underneath a well-supported hoop tunnel or inside an unheated greenhouse should suffice. Drape an insulated blanket over the device or add electric lights when needed.
Typically, temperatures in Zone 8 hover above freezing, but it can drop to -12°F occasionally. Some sections of the region can get snow and other sections get heavy rain. In the areas where there isn’t much wind, mulch will suffice as protection. However, it is advised that you stay alert to weather forecasts and cover crops with fabric if freezing temperatures are predicted. Row covers or another device should be used where the wind is strong or rain is heavy.
Zone 8 commonly experiences the first frost around November 15.
• Slowly maturing cold-hardy crops should be planted by August 1.
• Middle maturing cold-hardy crops should be planted by September 1.
• Quickly maturing cold-hardy crops should be installed by October 1.
A combination of mulch and row cover should protect the crop. Add a hoop tunnel when necessary.
Temperatures are typically mild in Zone 9. Mulch alone should suffice in semi-arid locations. A row cover with thin fabric may be necessary for rainy or windy sections. It is not uncommon for temperatures to drop to -7°F in extreme situations. Under those circumstances, protect plants with row covers made of old sheets or cloches made of plastic milk jugs cut in half.
The first frost usually hits Zone 9 by December 15.
• Slowly maturing cold-hardy crops should be planted by September 1.
• Middle maturing cold-hardy crops should be planted by October 1.
• Quickly maturing cold-hardy crops should be planted by November 1.
Watering And Harvesting
Once everything is set, the top priority for gardeners is to water and harvest. Winter gardens commonly need less water than summer gardens because there is less sunlight and evaporation. Moreover, mulch assists the soil to retain water and reduces the need to water by as much as 25 percent.
Cold frames will commonly reduce the need to water between mid-November and mid-February in most locations. Watering once a week should be sufficient for the rest of the cold season. Hoop tunnels and cloches could reduce watering needs as well depending on the setup and the climate. It is recommended that you feel the soil regularly and water when it feels dry.
It is recommended that you contact your local county extension office or consult with a garden center concerning more specific watering suggestions.
When you harvest it is suggested that you leave the roots in the ground and clip the leaves off as necessary. This encourages new growth and extends the life of the plants. Cold-hardy plants typically resist freezing and thawing as long as they are in the ground. However, they should be harvested when thawed. The optimum time is mid-afternoon when temperatures are above freezing.
Bring a covered basket or bucket to the garden to protect the veggies from freezing as you carry them back to your kitchen.