Now is the perfect time to reinvigorate your vegetable garden for a fall harvest. There are multitudes of vegetables that thrive during this period. This article will provide a few details of how you can plan and implement a fall garden that provides fresh vegetables until and even after the first frost.
In planning for a fall garden, there are four elements to consider. First, determine the size and the location of the garden. Second, amend the soil with compost, manure, and fertilizer if required. Third, you need to be aware of when the first frost is in your area. In this region of Virginia, the first frost occurs between October 15th and November 18th. The fourth and last element in your plan is the selection of vegetables. Many vegetables will thrive in the cooler fall temperatures; some may even withstand a light frost. Beets, broccoli, cabbage, cauliflower, peas, and spinach enjoy the cooler temperatures. Carrots, kale, lettuce, and parsnips can withstand the first frost and may even survive a winter if properly covered.
A fall garden is different from a spring or early summer garden because of two factors. These factors are called the Frost Tender Factor and the Fall Factor. The first, the Frost Tender Factor only applies to those vegetables that are most sensitive to frost such as corn, cucumber, tomato, squash, and beans. They should mature two weeks ahead of a frost for a successful harvest. You will need to carefully plan your time when planting to avoid the first frost before you harvest your vegetables.
The second, the Fall Factor, is the impact that cooler temperatures and shorter days have on vegetables. In an average seed to harvest period, this is about two weeks. So the gardener needs to allow for two extra weeks of growing. You can reduce some of this time by pre-sprouting seeds indoors. Allow them to reach about an inch before planting in the garden. This can reduce their growing time to harvest by 2 to 5 days.
If you choose to plant your seeds directly in the garden, plant them twice as deep as you would normally plant in the spring if the soil is dry and you cannot water the garden. Also, mulch the area to provide additional warmth to accelerate germination and growth. The following formula is for planting (with a few facts, you can calculate when it is the best time to plant almost any vegetable): Seeding to transplant time (or germination) in days plus Average growth from seedling to harvest time in days plus Fall Factor of 14 days plus Frost Tender Factor of 14 days equals days to count back from the first frost (when you start).
Let’s use bush beans as an example. Bush beans cannot withstand a frost, so use the Frost Tender Factor of two weeks. Bush beans take approximately 8-10 days to germinate and 50-55 days to grow until harvest. Don’t forget to add the Fall Factor of two weeks. Here’s what the formula looks like: 10 days (germination) + 55 days (seedling to harvest) + 14 days (fall factor) + 14 days (Frost Tender Factor) = 93 days.
If you use November 10th as the first potential frost date, then the best possible time for planting bush bean seeds is around August 9th. Remember to only use the Frost Tender Factor for those vegetables that are most sensitive to frost such as corn, cucumber, tomato, squash, and beans.
Keep in mind that first frosts are not always on the same day or even at the same time. The time span provided in this article is fairly wide. Pay attention to your local weather reports. These will usually announce the first frost. You will need to protect your frost sensitive vegetables. If it is going to be a light frost (usually 30 degrees or greater), then you can cover them (use baskets, burlap, boxes, or buckets). If it is going to be a hard frost, then you should pick your vegetables.
For additional information go to the Virginia Cooperative Extension at www.ext.vt.edu
• Len DePrisco is a Master Gardener intern with the Virginia Cooperative Extension Prince George County office. Virginia Master Gardeners are volunteer educators who work within their communities to encourage and promote environmentally sound horticulture practices through sustainable landscape management education and training. Virginia Master Gardeners bring the resources of Virginia’s land-universities, Virginia Tech and Virginia State University to the people of the commonwealth.