Spring is typically the most popular time for planting a vegetable garden. Many gardeners have not considered planting a fall garden because the common assumption is that the gardening year is over the closer to August and September it gets. Contrary to that popular belief, planting a fall garden can yield some of the best crops of the season.
Challenges of Fall Gardening
There are challenges ahead for those who do plant a fall garden but they are the same challenges that a spring garden presents. Weeds, insects and the weather are all issues that will need to be addressed. Weather is where the difference becomes the most apparent. Instead of dealing with early season cold temperatures and fighting the late spring freeze events, the gardener is working against hot temperatures early on in production and then falling temperatures taking their toll at the end of the season. Another weather factor to take into account is the reduced moisture levels that are associated with late summer and early fall.
The warmer temperatures that are normal when planting a fall garden present several challenges. Many types of seed have a reduced germination rate at higher soil temperatures so strategies need to be developed to counter those higher soil temperatures. Germinating the seeds indoors and then carefully transferring them to the garden can be one tactic used. When using this method it is important that the newly planted sprouted seeds are kept well watered once moved to the garden. A second strategy is planting the seeds ½ inch to 1 inch deeper than normally called for depending on the size of the seed. Increasing the soil depth even slightly will help reduce the temperature of the soil near the seed. Lightly mulching will also help reduce soil temperature. With higher temperatures the soil also dries out quicker after watering and tends to crust, hindering the emergence of germinating seeds. Keeping the soil moist in this situation until sprouting is complete is important for the plants survival.
Benefits of Mulch to the Fall Garden
Mulching is a very important part of the fall garden. Mulching help reduce soil temperatures by shading the soil and absorbing much of the sun's energy. It also helps the soil retain moisture reducing the supplemental watering needs of the garden since natural rainfall during this time can be scarce. Another advantage that mulching offers is that it will help reduce weed populations. Weeds thrive in the hot, dry conditions that late summer and early fall offers and mulch will help smother out germinating weed seed.
When using mulch it is important to use the right amount for the task at hand. To reduce the soil temperature for newly planted seeds, it is important to use a very light covering of mulch taking care not to smother the emerging plants. For water conservation and weed control, 3 to 4 inches of mulching material will give good results. Leaves, grass clippings, straw or compost are all good mulch material to use in a vegetable garden.
Vegetable Variety Selection
One of the most important considerations when planning for a fall garden is the choice of varieties that you will be planting. Varieties that thrive in the spring may not perform the same in the fall and be failures. Varieties that do well in the fall prefer long, dry days early on in the season and shorter, moist, cool days as they mature. A second consideration is planting time. You must time your planting to allow enough grow time for your crop to mature and produce. Most seed packets provide the number of days from planting to harvest.
Warm season crops such as squash, cucumbers and tomatoes must be planted early enough that they will yield prior to the first frost since they will not withstand any freezing temperatures. Cool season crops such as lettuces, radishes and spinach on the other hand are capable of withstanding dips in temperature into the freezing range for varying amounts of time depending on the crop. It is important to remember that often times there are freeze events that last only a short period of time and then there may be several days of great gardening weather to work with. There are also vegetables that are considered hardy and can withstand several frosts and can take temperatures into the 20’s. These include kale, carrots, broccoli and Brussels sprouts.
To determine when to plant you need to know the number of days from planting to harvest and the average first frost date for your area. In Nebraska the first frost date ranges from the last week in September to the last week in October depending on location. For example, if planting summer squash, a warm season crop and has a 50 day from planting to harvest growing period, you would add 50 days plus 14 days for a harvest period and then add 10 days for the “fall factor” for a total of 74 days. Using a frost date of October 10, subtract 74 days for the planting date in the vicinity of August 1st. The “fall factor” used in the equation takes into account the shorter day length of fall.
Following is a partial list of vegetable crops and varieties that do well in the fall garden:
- Beets—Ruby Queen, Red Ace, Pacemaker II
- Broccoli—Packman, Premium Crop
- Cabbage—Early Jersey, Wakefield, Red Express
- Carrots—Danvers Half Long, Scarlet Nantes, Little Fingers
- Cauliflower—Early Snowball, Snow Crown
- Cucumbers—County Fair, Sweet Slice
- Lettuce—Grand Rapids, Salad Bowl, Buttercrunch, Red Sails
- Radishes—Early Scarlet Globe, Cherry Belle, White Icicle
- Spinach—Olympia, Kan Aji, Renegade