Category Archives: The First Time Gardener
When to Plant
The general recommendation for planting a fall garden is to plant most vegetables starting in late July through mid-August. A few vegetables that need colder temperatures and grow quickly, such as lettuce, radishes, spinach, and turnips are generally planted from mid-August to mid-September. However, sometimes the summer weather does not recommend itself to those planting ranges.
Watching the Weather
When the weather in late July or early August is very hot and dry, it may be preferable to wait to plant many fall crops for a couple of weeks, even though that may delay harvest or result in smaller harvests. The heat can make it extremely difficult to germinate seeds successfully outdoors. It can also be a challenge to establish transplants at that time. It is important to watch the weather closely and be ready to plant as soon as there is a slight break in hot weather. Even if the daytime highs are still hot, when the overnight temperatures drop below 70 degrees, most fall vegetables will be able to survive.
Taking Risks for Late Plantings
If the weather is not favorable in the late summer, it is still possible to plant many fall vegetables later than the general recommendations. The success of these plantings depends on how long mild fall weather persists. Often we do not have consistently cold temperatures until mid-November, giving many vegetables extra time to mature if planted late. Row covers can also keep plants warmer to promote continued growth.
Vegetables that mature quickly, such as radishes, lettuce, and other salad greens, can be planted multiple times over the course of 6+ weeks to provide harvests throughout the fall. Seeds planted in late August will grow quickly, while seeds planted in late September will typically be slower growing. To successfully stagger crops, you should plant 1 week apart in August and stretch that out to 2 weeks apart by late September. Using both transplanting and direct seeding will also help stagger your harvests of these vegetables.
Early August – Plant lettuce seeds indoors
Late August – Transplant first lettuce seedlings, plant lettuce seed directly in the garden
Early September – Transplant second lettuce seedlings, plant more lettuce seed directly in the garden
Late September – Harvest lettuce from first transplant group
Early October – Harvest lettuce from second transplant group
Mid- to Late October – Harvest lettuce from first and second direct seeding groups
See Part 1 here.
Some vegetables are not commonly grown in Kansas gardens because our climate is a challenge for them. These vegetables will often thrive in a fall-planted garden, although the results may be variable.
Chicories, related to lettuces, include endive, escarole, Italian dandelion, and radicchio. These are vegetables that do the best in cool conditions and are quite cold hardy. Radicchio in particular has best color development and flavor as the weather gets colder. While we cannot always grow vegetables of the size you might see in the grocery store, you can grow a crop that is good to use in your kitchen. Chicories are best started indoors from seed in mid- to late July and then transplanted outdoors in late August or early September.
While the leafy types of fennel grow well in the spring and early summer, if you want to try growing the bulb-forming types of fennel, the fall is the best time to grow them. The longer, more consistently cool weather will allow for the production of a better quality bulb. Bulbing fennel planted in the spring may bolt (flower) before producing a good bulb. Bulbing fennel can be started indoors and transplanted or direct seeded.
Fall or Winter Radishes
The small, spicy spring radishes are well known to Kansas gardeners, but the larger fall radishes are much less common. Many of these radishes are Chinese or Oriental radishes, such as the daikon. Other varieties include Watermelon radishes (aka Red Meat or Mantanghong varieties), Black Spanish Round radishes, and a variety of other Chinese specialty radishes. These radishes are usually large – the size of a baseball for the round types or larger than most carrots for the daikons.
Fall radishes are typically sweeter and less spicy that the spring radishes, and are often used in cooked dishes rather than just salads. Fall radishes will also store longer under similar storage conditions to turnips, carrots, and potatoes in a root cellar.
Bok Choy is an Asian green that is becoming common in grocery stores. It has crunchy, stems similar to celery and dark green leaves. This vegetable is frequently found in Asian stir fries and can be used much like celery in many dishes. Bok choy grown in the spring will often become strong flavored, even bitter quickly. It will also flower before a good quality rosette of leaves has developed. While fall grown bok choy may also bolt in a warm spell, the quality of the vegetable is much better than in the spring, in most years.
Like onions, leeks can be planted again in the fall. Leeks should be started indoors and then transplanted in the fall to provide a longer growing season. Fall planted leeks may not be as large as leeks planted in the early spring, but they are very cold hardy and can be harvested well into the winter. Some types of leeks will also overwinter successfully in southern Kansas, allowing for continued growth in the spring.
Over the next several weeks, I’m going to be sharing several excerpts from a publication I recently wrote about Fall Vegetable Gardening. Here’s the first bit!
Why a Fall Garden?
Fall gardens in Kansas can be very productive and enjoyable after a hot summer. While many of our summer vegetables will continue to grow and produce until frost, a well-planned fall garden can provide vegetables into the early winter, while some plants can be over-wintered to get an early start the following spring. Cooler temperatures make it refreshing for gardeners to spend more time in the garden again during the fall.
What to Plant
Vegetables for fall gardens generally fall into the “cool season” vegetable category. These are vegetables that prefer the cooler, more moderate temperatures of the spring or fall in Kansas. Many of them will also tolerate cold weather in the early winter.
Types of Vegetables
- Leafy salad greens
- Root vegetables
- Brassicas (broccoli, cauliflower, cabbage, etc)
While not every vegetable in each of those categories is a good choice for fall, many of them will do very well. Lettuces, spinach, arugula, Swiss chard, Asian greens, collards, beets, carrots, turnips, radishes, some onions, chicories, kale, broccoli, cauliflower, broccoli raab, leeks, and other related vegetables do well in fall plantings.
Vegetables that Grow Best in Fall
Although our fall weather can still be quite hot at times, the trend is always toward cooler temperatures. This allows for some vegetables, especially the Brassicas, to be more productive and better quality in the fall. Often when planted in a warm spring, they will go directly to flower (bolting) rather than producing a good crop. Cauliflower in particular may be more productive and of better quality when planted in the fall. Bok choy and other Asian greens will also be much less likely to bolt and develop a strong flavor in the fall. Likewise many lettuces will have a crisper, sweeter characteristic in the fall.
Vegetables that Do Not Grow Well in the Fall
A few vegetables that we plant in the spring will not be as productive in the fall.
- Peas love cool weather, but they also require a cool soil for good germination. Our soil temperature is typically too warm in early fall for the peas to germinate and produce well. When planted later in the fall, they may not have enough time to mature and produce a crop (although you can get some awesome pea shoots that can be a delicacy! Another blog reminded me of this a few days ago.). Snow peas may be more successful when planted in late August than other types of peas.
- Potatoes can be planted for a fall crop in the northern parts of Kansas, but in southern Kansas the soil is too warm and usually the yields are poor on fall planted potatoes.
- Fall planted onions will produce great green onions and some small onions, but they will typically not produce the large storage onions due to the shorter season. Some types of onions may do better than others, and some may also overwinter well, producing larger onions in the spring.
Choosing Varieties for the Fall Garden
While you can often use the same seeds you planted in the spring to grow again in the fall, there are also times when it is beneficial to choose different varieties specifically for fall plantings. Depending on your planting plan, you may want to look for varieties that have more heat tolerance for the late summer transplanting. You may also want to consider varieties with great cold tolerance to allow your garden season to stretch even further into the winter. Another consideration on some crops is to choose a variety with a shorter “days to maturity” to ensure that you get a crop before it gets too cold, especially if you end up planting later due to hot weather in August.
Every spring when the weather turns warm it can be tempting to jump the gun and plant our tomatoes and peppers too early. However, just because it is getting into the 60s, 70s, or even 80s during the day doesn’t mean that it is the right time to plant heat-loving vegetables like tomatoes and peppers. There are a couple of things to keep in mind – overnight temperatures and soil temperatures.
Even though the chance of a frost is fairly minimal after mid-April, we are still frequently getting down to temperatures in the mid-30s to mid-40s overnight. Tomatoes and peppers will not be killed by these temperatures, but they will be shocked and potentially damaged by exposure to those temperatures. Planting tomatoes and peppers without any protection from overnight temperatures will result in little to no growth until the weather is consistently warmer. Plants that are set out in early May will quickly catch up with plants set out earlier because of the difference.
Even more important that overnight temperatures is the soil temperature. The soil typically is slower to warm up than the air, and tomatoes and peppers need a soil temperature of at least 55 degrees F (and they really prefer 60 degrees F). Cold soil has the same effect (and sometimes a bigger effect) than cold air. Not only will the temperature shock the plants, it can also induce a phosphorus deficiency. If you observe a purple coloration to the leaves or stems of your plants, that is phosphorus deficiency. Usually it is not due to a lack of phosphorus in the soil but to the cold temperatures that prevent the plants from absorbing the phosphorus.
It is very easy to test your soil temperature to see if you are ready to plant. Just find a thermometer that will measure the right temperature range and stick the probe about 2-3 inches into the soil in late morning. This will give you a good average soil temperature in your garden.
Ways to Plant Earlier
Normally, I just wait to plant until the conditions are right in early May. However, if you want to plant earlier, there are a couple options. Many home gardeners like to use different types of water teepees to keep the ambient temperatures warmer around the plants. You can also choose to warm the soil by using clear or black plastic spread over the soil. Tomatoes and peppers can be planted right through the plastic. The warmer soil temperatures will enable the plants to grow more quickly in the spring.
Are you still confused by trying to figure out the right time to plant different vegetables? Check out this video, where Evelyn Neier explains the difference between cool season and warm season vegetables and what that means for gardeners in Kansas.
You can catch more videos from K-State Research & Extension here: KSRE YouTube Videos