Wait to Harvest These Fall Veggies After a Frost—Here’s Why

Did you know some veggies taste better if you harvest them after a light frost or two? While tender plants like tomatoes and peppers need to be picked before frost hits, some hardy crops actually get sweeter and tastier in cold weather.

Here’s a look at why frost improves the taste of certain veggies, and a list of common crops that taste best after a kiss of frost.

Why Do Veggies Taste Better After Frost?

When plants photosynthesize, they convert carbon dioxide, water, and sunlight into sugars, which plants store in the form of starches. But when the weather cools in autumn, some cold-hardy plants begin to release enzymes that convert those stored starches back into sugar.

Plant sugars usually concentrate in plant leaves and roots and act as a sort of natural anti-freeze that keeps plant cells from bursting in the cold. However, the sugars also work to counteract bitter flavors in certain veggies, which is why some cold-hardy crops taste sweeter and better after frost.

Timing Your Harvest

Exactly when to harvest veggies will vary depending on the plants you’re growing and your local climate and growing zone. Tender veggies, like tomatoes and peppers, usually need to be harvested before frosts and freezes hit, but cold-hardy crops can remain in the garden much longer.

Some cold-hardy plants tolerate a few light frosts, while other crops survive short periods of freezing weather. In general, however, it’s usually best to pick cold-hardy veggies after the first frost or two, yet before freezing temperatures set in and the ground freezes solid.

That said, you may be able to extend your growing season by weeks or even months and harvest cold-tolerant crops through winter if you cover them up with cloches, row covers, or frost blankets.

Top Vegetables to Pick After Frost

Crops that taste better after frost typically fall into one of three categories: root veggies, brassicas, and leafy greens. These vegetables all handle light frosts well, and potentially some freezing weather too. However, they need to be harvested the right way if you want to get the best and sweetest flavor.

Root Vegetables

Light frosts can make root veggies a little crunchier and so sweet that harvests are often described as tasting “like candy.” But if you want root crops to taste the best, be sure to plan ahead and get your crops planted at the right time. Although root veggies can handle cold weather, they don’t grow as quickly or as well when temperatures start to fall, and crops that are planted too late in the season may not have enough time to produce big roots.

Most root veggies should be planted from late summer to early autumn to ensure they have enough time to mature. Then, cover plantings with a loose layer of straw mulch to insulate the soil and consider adding row covers over your plants so their leaves don’t get damaged by the cold. Root crops usually withstand a few light frosts and potentially a short period of freezing weather, but they should always be harvested before the ground freezes.

Some root vegetables that are known to sweeten up with frost include:

• Carrots
• Parsnips
• Beets
• Rutabagas
• Winter radishes
• Leeks
• Turnips
• Celeriac

Brassicas

Planting brassicas in late summer to early fall is a smart choice for a few different reasons. First, brassica pests are less likely to be active at this time of the year, which means you won’t need to worry as much about damage from cabbage loopers and other pesky insects. But beyond that, brassicas also get sweeter in cold weather, and chilly temperatures mellow out the bitter flavors that are sometimes associated with these plants.

Like root veggies, brassicas grow better with a bit of mulch. They need consistent moisture even in cold weather, so water in the absence of rain. Covering these plants with frost blankets or cloches also extends the harvesting too, but brassicas usually have the best flavor if they are picked right after the first or second frost.

Most brassicas taste sweeter if they are harvested in cold weather, including popular edibles such as:

• Broccoli
• Cauliflower
• Cabbage
• Brussels sprouts

Leafy Greens

Cold weather concentrates plant sugars in plant roots, but it also makes leafy greens sweeter and tastier. Because leafy greens grow faster than brassicas and root veggies, you have a bigger planting window that may extend into early fall. Just keep in mind that these plants won’t grow as quickly when temperatures drop.

Row covers, cloches, and grow tunnels are particularly helpful when growing leafy greens in autumn, but these coverings should usually be removed during the day to allow your plants to “breathe.” With nighttime protection, most leafy greens can continue to be harvested even when temperatures fall below freezing; however, frozen leaves should be allowed to thaw before you pick them. If you harvest leafy greens while they’re still frozen, there’s a good chance those leaves will turn to mush before you get the chance to eat them.

Some leafy greens that you may want to harvest after frost include:

• Kale
• Swiss chard
• Collard greens
• Spinach
• Tatsoi
• Arugula
• Bok choy
• Radicchio
• Endive