The Fall Vegetable Garden

Broccoli

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

A grassy invader

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.

Stiltgrass close

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

a native pollinator favorite

Echinacea pupurea

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.

Echinacea flower

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

Home Gardeners’ School 2019

The 23rd annual Home Gardener’s School will be Saturday, June 1 from 8:30 am to 3:30 pm.

The Home Gardeners’ School is a day of gardening inspiration, learning from top regional gardening experts, and an opportunity to meet with fellow gardeners. 

This event is hosted by the Master Gardeners of Delaware County at the Education Center in Smedley Park in Springfield, Pa.

You don’t have to be an experienced gardener to attend this event. All levels of experience are welcome.

The day includes 3 activity sessions. Create your own perfect day by choosing your favorite activity for each session.

Bid in the silent auction to win unique plants, gift certificates, books, and other items of interest to gardeners.

And of course our Master Gardener Marketplace with a fabulous selection of outdoor planters: big, small, short and tall! Great for pollinator pots, veggies and ornamentals plus a variety of plants. Unique MG-made items found nowhere else.

Registration and shopping begin at 8:30 am. Our educational sessions are summarized below. You can register on line here.


9:00 – 10:15 Session Choices:

Lecture A – Nature Nurtures – The Power of Plants – Louise D. Clarke, Horticulturist, Morris Arboretum –  Enjoy a fascinating presentation on the scientific evidence that demonstrates the positive effects of the natural (outdoor) environment on both our physical and emotional well-being. Cost $20

Workshop A – Herb Vinegars, Dips & Spreads, Oh My! – Jane Nyiri, Master Gardener -Taste fresh herbs in dips and spreads and enjoy a hands-on experience in making your own herb spread and vinegar to share with family and friends. Recipes will be shared. Limited to 15. Cost $25

Workshop AA – Build a Bird Feeder – Frank Foxwell, Master Gardener – Join Frank in assembling your own birdfeeder for Baltimore Orioles, Catbirds and Scarlet Tanagers. Suitable for mounting outdoors, each feeder has locations for jelly, apples, and oranges. Bring portable drill (Philips head driver, 1/8” & ¼” bits) & hammer. Limited to 15. Cost: $25

10:30 – 12:00 Session Choices:

Lecture B  – Developing Curb Appeal – Duncan Himmelman, PhD, Mt. Cuba Center Educator – Learn how to revitalize your front yard to meets your needs, provides year-round horticultural interest and variety, and increases your property value. Cost $20.

Workshop B – Wood Base Moss Wreath with Clay Pots & Succulents – Joe Daniels, Master Gardener – Create a sensational wood base moss wreath with sedums in clay pots to decorate your summer garden. Hands-on workshop, plants included, bring gloves. Limited to 15. Cost $25

12:00 Noon – Lunch

Purchased lunch selection available through on-line registration.

1:00 – 2:30 Session Choices:

Lecture C – Let’s Look at the New Perennials for 2019 – Sharee Solow, Designer & Owner, Solow Horticultural Designs – Find out the best new plants for your garden this year. Sharee will review the “best of the best” new perennials for 2019, highlighting the ones that will thrive in our area. Cost $20.

Workshop C – Building Your Own Bamboo Trellis or Tuteur – Julia King, Master Gardener – Bamboo is a wonderfully versatile building material and one of the world’s most renewable resources. It’s lightweight, strong, and flexible, and it looks at home in most garden designs. Build your own ornamental trellis or tuteur for your clematis, beans or any other climbing plant in need of a little support on its skyward growth path. Limited to 15. Cost $25.

Workshop CC–Master Gardener –Summer Sippin’ Herb Container – Brenda Troutman, Master Gardener – Grown for their versatile use, herbs are some of our oldest plants. Learn their preferred growing conditions and the new ways to incorporate them into your garden and containers. Each participant will plant a beverage herb container to take home for their summer drinks. Limited to 15. Cost $25.

Annual Garden Contest 2019

Are you proud of your garden and believe it is worthy of notice?  Enter the Delaware County Master Gardener 2019 annual Garden Contest being held this summer.

For more than 20 years, the Delaware County Master Gardeners have been sponsoring a garden contest for Delco residents as a way to way to educate and empower gardeners to beautify their environment . 

The contest is open to individual gardeners as well as community gardens in both ornamental and vegetable categories.  We welcome all gardens that merit attention. 

Sub-categories for the contest include:

Ornamental Gardens:

  • Native/wildlife – use of native plants that attract and sustain wildlife
  • Pollinator Gardens – use of plants that attract bees, birds, and butterflies
  • Landscape Design

Vegetable Gardens:

  • Individual
  • Community Gardens
  • Youth Gardens
  • Novice Vegetable Gardens for first year gardeners

Garden judging takes place on June 14th for the ornamental garden categories and August 9th for the vegetable garden categories .

You can download a copy of the contest registration form here.

Winners will be notified by mail. First, second and third place winners in each category are invited to our Fall Fest in September 28th in Smedley Park to receive their ribbons.  

Weed Watch – Lesser Celandine

Lesser Celandine may have cheerful yellow flowers, but don’t let it fool you. This is an aggressive, non-native thug that is wreaking havoc in our natural landscapes (not to mention front yards, back yards, flowerbeds and lawns).

Lesser Celandine (known as Ficaria verna but sometimes still listed as Ranunculus ficaria ) was brought from Europe in the 1860’s as an ornamental plant and escaped cultivation. The plant has shiny, dark green, kidney shaped leaves and bright yellow flowers. It typically emerges in late January to early February.

Because it emerges so early and creates a very dense mat of leaves, it smothers many of our native spring wild flowers by blocking out light, air and growing space before they can even get started. Our native insects are then deprived of the pollen and nectar they need early in the season.

Lesser Celandine is an ephemeral and is usually dormant by late June. This can cause problems in wetlands because other plants have been snuffed out so there is not as much vegetation left to prevent soil erosion in late season flood events.

Lesser Celandine is a very vigorous spreader, mainly through underground tubers and bulblets attached to the leaf stems. It prefers moist soil, but can survive in drier areas. It can colonize an area very quickly.

The tubers and bulblets can be spread by animals, by flooding and even by well meaning gardeners. It is often seen along stream banks where it has been spread by water flow.

Managing Lesser Celandine is very difficult. Small infestations can be weeded out, but you must remove all the tubers and bulblets. Weeding can actually spread the weed if you are not careful. To help contain the spread, keep in mind:

  • Never put removed Lesser Celandine in the compost.
  • Do not pile it on the ground or rake it up, put it directly in a disposal container. You may need to dispose of some soil along with the tubers to ensure you have removed it all.
  • Mowing Lesser Celandine can fling the small bulblets into other sections of the lawn.
  • When the plant is dormant, its easy to move the tubers from one part of the garden to another when transplanting other plants.

It is possible to eliminate Lesser Celandine with herbicides, but the window of opportunity is small. Here are a few references that discuss the use of herbicides.

Pollinator Display Garden

Learn about pollinators at the display garden in Smedley Park.

Article by Louise Sheehan and Heather Gray

One community educational endeavor in which Delaware County Master Gardeners are engaged is the creation and maintenance of various display gardens.

One such garden is the Pollinator Garden. Located on the Penn State extension grounds at Smedley Park, it was founded in 2002 and is replete with mostly native plants that sustain butterfly, bee, and bird pollinators. The purpose of the garden is to inform the public about native plants that attract pollinators.

These pollinators are essential in moving pollen from one plant to another in an effort to produce more plants.  Selecting native plants sustains the natural wildlife and beauty that is unique to our region.

Some plants in the garden are penstemon, bronze fennel, monarda, echinacea,and lobelia cardinalis. This variety of native plants has attracted a delightful diversity of butterflies, including monarchs, pearl crescents, silver spotted skippers, black swallowtails, to name a few.

Insects and animals are essential for pollination. The seeds produced through pollination are the basis of our ecosystems. These plants stabilize the soil and purify the air. Pollinators are also responsible for much of our nutrition; without them, we would not have an ample supply of fruits and vegetables.

Tending the garden begins in early spring with a general clean-up and deciding what additional plants should be purchased or replaced.  Each week throughout the summer, the Pollinator Garden Committee members, maintain the garden by weeding, watering, replanting, pruning, etc.

In 2013 the garden received the Community Greening award from the Pennsylvania Horticulture Society. It also earned a Penn State Pollinator Friendly Garden Certificate.

The public is invited to visit the garden to view the flowers and pollinators and to learn which plants to choose for their own gardens or to just sit and enjoy the beauty and richness of the garden. To aid gardeners in selecting plants, a brochure entitled How to Grow Your Own Pollinator Garden was designed and created by some of the committee members and is available at the garden. It provides the public with key information on the plants in the garden.