The Fall Vegetable Garden

Believe it or not, now is the time to start thinking about your fall vegetable crops. 

The fall vegetable garden can sometimes be a bit challenging in our climate because soils are often hot and dry in July and August. This can prevent seeds of cool season crops from germinating. 

One way to get around this is to start these vegetables indoors where the temperature and moisture can be controlled. Start the seeds in mid-July and then transplant the seedlings into the garden in mid-August. Be sure to properly harden off the seedlings before transplanting.

Plants that respond well to this technique include broccoli, cabbage, cauliflower, brussel sprouts, collards, kale, lettuce and spinach.

If you would prefer to direct seed all you crops in the garden, there are a couple things you can do to increase the chance of success.

Make sure the seeds are kept moist until the seedlings are well established. On very hot days, this may mean watering more than once.

If possible, provide some temporary shade for your seed bed until the seedlings are well established, particularly during the hottest part of the day. You may be able to plant some of the seeds in places where they get some afternoon shade from existing plants.

If some of your warm season crops (cucumbers, beans, summer squash) are looking a bit tired or worse for wear, you probably still have time to plant another sowing of seeds and harvest another crop.  Just look at the days till harvest on your seed packet and make sure you have enough days until the first expected frost. You can find the first expected frost date for your exact location here.

Want more information? Here are some links:

National Gardening Association – When to plant vegetables

Cornell Extension Vegetable Growing Guide

Delaware Cooperative Extension –Vegetable Garden Planning Schedule

Weed Watch: Japanese stiltgrass

Japanese stiltgrass (Microstegium vimineum) is a non-native, invasive, annual grass. It has lance like leaves with a silvery stripe down the center, arranged alternately on a thin, wiry stem somewhat like a very miniature bamboo. It normally is 2-3 feet tall at maturity in late summer with seed heads at the top of each stem.  

Stiltgrass was probably introduced into this country as packing material in shipments of goods from China in the early 1900’s. Since then it has made itself at home in open woodlands, paths, roadsides and of course lawns and flowerbeds.

Stiltgrass has the ability to form dense stands that crowd out and smother native and desired plants. The stems root at the nodes, allowing a single plant to advance across the ground.  While stiltgrass is an annual and the parent plant dies in winter, it creates an enormous amount of seed and quickly builds up a bank of seeds in the soil. Each plant can produce up to 1000 seeds and they remain viable in the soil up to 5 years. The key to control is preventing new seed production and preventing germination of the existing bank of seeds.

The plants are shallow rooted and can be pulled by hand. Plants should be removed before mid-August when the seed matures.  Cutting or breaking the plant stems earlier in the season may stimulate them to create and drop seed early, so try to remove each plant completely. The process of weeding may disturb soil and expose more seeds from the seed bank, encouraging new weeds. Mulching directly after weeding will help prevent germination of new seeds. Planting desirable plants densely to leave less open garden area may also help prevent stiltgrass germination.

Plants in a mowed lawn will still create seeds at the lower height. If possible, wait until just before the seed matures to cut large stands of stiltgrass so there is not enough time before winter cold for seed development.

There are some options for chemical control of stiltgrass.  This article from Penn State Extension describes those options.

Want a little more information? Here are some links:

Penn State Extension – Controlling Japanese Stiltgrass in Your Garden

PA Dept. of Conservation and Natural Resources: Japanese Stilt Grass PDF

The Humane Gardener – How to Fight Plants with Plants

Plant Profile: Echinacea purpurea

Echinacea purpurea has the common name Purple cone flower.  It is a lovely herbaceous perennial that is native to eastern North America. Its showy blossoms usually appear in late June to early July and can rebloom through August. The blooms are very attractive to bees and butterflies making Echinacea a great addition to a pollinator friendly garden.  Gold finches will also visit the flower heads as they ripen to eat the seeds.

Echinacea grows best in full sun, but will take some shade. It requires well drained soil and is tolerant of drought and poor soil. It grows 2 to 5 feet tall depending on the cultivar and for the most part is self-supporting, but may need some support if grown in rich soil or too much shade.

Echinacea generally will continue to bloom whether spent blossoms are removed or not, but removing spent blossoms early in the season may make the plant look more tidy. Consider leaving some spent blossom seed heads over the winter as a food source for birds, but be prepared for some self-seeding around the base of the plant.  I consider this a bonus, and simply move the volunteer seedlings where I want them in the spring. Echinacea is also used as an herbal supplement to boost the immune system.

While called purple coneflower, the common version is more of a pinkish-purple and it has been hybridized into a variety of different colors including white, yellow, orange, red and even bi-colors. Some varieties are quite fragrant.

There are also coneflowers that have been hybridized with double or triple the petals to create a “pom-pom” effect, but note that these doubles and triples are not useful to pollinators because the hybridization process eliminates nectar sources.  These hybrids are also mainly sterile, so they do not provide seeds for birds.

Echinacea can be susceptible Aster Yellows. This is a disease caused by infection by a microorganism called a phytoplasma. The infected plant’s flowers will remain green and the cones will be distorted with leaf like projections.   The disease can be spread from an infected plant to a healthy one by leafhopper insects as they feed on different plants so it is important to remove any infected plants you find. There is no cure for Aster Yellows.

Echinacea are sometimes bothered by Japanese beetle which chew the flower petals but they usually out-grow “beetle season” and continue flowering.   

Want a little more information on Echinacea? Here are some links:

Ladybird Johnson Wildflower Center profile

Penn State Extension – Echinacea Diseases

Iowa State Extension: Yellows Disease of Purple Coneflower

National Institute of Health of Echinacea Herbal Properties