Carrots are both steadily in demand and amenable to season extension efforts. By making multiple succession plantings of Early, Main Crop, and Storage Varieties, you can extend the carrot harvest window and meet year-round demand for this standby crop. To best achieve this, you will need to sow at 3-week intervals, know a little about which types to plant in which sequence, and which ones work best for overwintering and winter harvest.
Johnny's line of carrots is selected to provide for the broadest range of growing conditions and widest possible harvest window. Here is how to get the most from your carrot succession planting program.
Spring Sowing for Summer Harvest
Most types of carrots can be planted in the spring for summer harvests. There are a few exceptions to this, involving variation between different varieties' reproductive triggers and changes in flavor with temperature.
- Bolting. Carrots are biennial, taking two years to complete their lifecycle, so they require a "cool" season in order to produce seed. By virtue of this requirement, some types, when exposed to cool spring weather as juveniles, may bolt — produce flowers and go to seed. Kuroda and purple varieties, in particular, typically bolt prematurely when sown in cool spring conditions. The types that more readily bolt have a higher cold-dormancy threshold temperature than those that do not bolt as readily. When this threshold is met, these types depart from the energy-gathering/storing, root development phase of the life cycle, toward the reproductive, flowering/seed-production phase. When carrots send up flower stalks, the storage portion of the plant becomes woody and fibrous, rendering the crop unmarketable.
- Flavor. Though most types can be planted in the spring for summer harvest, in some varieties, maturation during the warmer weather of summer can result in off-flavors that are unpleasant.
As a result of these factors, it is important to choose the right varieties for your spring sowings. Look for these three criteria when choosing which varieties to plant in spring:
- Varieties described as having good flavor even in warm conditions.
- Earlier-maturing varieties, so they will be ready to harvest before temperatures become too warm.
- Types / varieties that will not bolt early.
Fall Harvest Carrots
Just as the flavor of some carrots can be ruined by warmer temperatures, fall-harvested carrot flavor tends to be better because the roots mature under cooler conditions. After a few light frosts, carrot roots may become even sweeter, which explains why fall-harvested carrots are so popular.
Once heavy frost threatens, however, your best bet is to either:
- Mulch beds with thick layers of straw (or whatever is on hand), if feasible; OR
- Cover beds with some thick row cover; OR
- Harvest the roots before heavy frost and prep for storage.
To learn more, read our recommendations on Carrot Harvest, Post-Harvest Handling, & Storage.
Winter Harvest & Overwintering Carrots
Depending on your location, you may be able to leave carrots in the ground for harvesting through the winter into early spring. This can be facilitated by either mulching heavily or by planting your carrots in tunnels — a choice which is again dependent upon climate and weather, as follows:
- QuickHoops™ Low Tunnels are ideal in locations where there is little to no snowfall, allowing the plastic to be easily removed to harvest roots when needed.
- Traditional Low Tunnels or caterpillar tunnels are ideal for higher latitudes, as doors can be affixed to their endwalls, providing for ready access to the roots after snowfall.
Even in areas where low tunnels are appropriate, heavy row covers and mulching may need to be applied. The trick is to keep the soil insulated just enough to allow for easy digging of the roots throughout winter.
If the tunnel space can be justified for overwintering your carrots, there are a few advantages to this approach that digging and storing your carrots cannot provide:
- Overwintered carrots still have green tops. While the tops may appear a bit tattered and torn by mid to late winter, they can be snipped at 1–2" above the root shoulder, giving your overwintered carrots a fresher look that distinguishes them from stored carrots.
- You can dig carrots from tunnels whenever needed.
- "Storing" your carrots in the ground means additional free space for other purposes in your storage area.
Once you know which types to plant and when, extending the carrot harvest window is relatively easy to accomplish. Johnny's line of carrots is selected expressly to accommodate a range of conditions and help you provide a year-round supply of this versatile, popular vegetable. We encourage you to explore planting sequences, intervals, varieties, and methods to determine the practices that work best for you.
- Next up in our carrot-growing series: Harvesting, Post-Harvest Handling & Storing Carrots »
- How to Grow Carrots, with Dr. John Navazio »
- Organic Variety Trial Reports • Collected reports from around the US on organic crop performance »
- Johnny's Blog • Why Grow Carrots? Flavor, Diversity & Marketability »