The Transylvania Times -

By Joyce Pearsall
Transylvania Extension Master Gardener 

Host Plants In Your Garden And Yard


According to the “Free Dictionary” by Farlex, in “agriculture a host plant is one which aids, shelters or protects another plant in its growth.” There are also host plants for many butterflies and moths, plants which provide food for the larvae of these insects.

Many insects are “generalists,” using a variety of plants, but some have one and only one host plant. An example is the monarch butterfly whose only host plant is milkweed (Asclepias). Since in recent years the monarchs have lost habitat the size of Texas, and their numbers are critically low because of that, it is important to restore their habitat. Some of the milkweed loss is directly related to use of herbicides, pesticides and insecticides. Development has also infringed upon milkweed growth.

Some positive action we can take involves creating Monarch Waystations, gardens that contain milkweed as well as nectar sources that will bloom spring through fall. Even two swamp milkweed (Asclepias incarnata) in containers will attract monarchs! Since their root system clusters, containers do work well. The monarchs will use Butterflyweed (Asclepias tuberosa) if there is no other milkweed around. It is not the very best plant for the larvae, but even this is better than none. These have a tuber-like root and may also grow in containers.

Common milkweed (Asclepias syriaca) is the best plant for them, and once established, in about four years, it will spread by rhizomes. In our Transylvania County Waystations, we have three varieties of milkweed. This season, the females laid eggs on the common variety more than the swamp variety and none on the butterflyweed. We also have poke milkweed (Asclepias exaltata) — a nice woodland-edge plant with a tap root, where I found one or two larvae this year. Note that butterflyweed is not butterfly bush (Buddleia). The butterfly bush, to the best of my knowledge, is not a host plant but is a nectar source; but purchase the sterile variety, which won’t spread and become invasive.

When in bloom, milkweed has attractive and fragrant flowers — an awesome nectar source. After the flowers die and droop, they change into seed pods. The mature seeds are then used to grow other milkweed. Some people use the cottony fluff that’s attached to the seeds for doll hair as well as waterproofing and insulating clothes. The pods are often used for crafts.

Stop by the Silvermont gardens established by Extension Master Gardener Volunteers to see an example of a Monarch Waystation/Pollinator Garden. Other gardens there include woodland, vegetables and fruits. It’s a great educational site!

In the Silvermont gardens you will also find both nectar and host plants. Some examples:

• New England aster (Aster novae-angliae) is an important fall nectar source and hosts the pearl crescent butterflies.

• New York ironweed (Verononia noveboracensis) is also a fall nectar source and hosts American painted lady, painted lady and the pearl crescent butterflies.

• False blue indigo (Baptisia Twilite Prairie Blues-hybrid) flowers in the late spring and early summer. It hosts the orange sulphur, clouded sulphur, frosted elfin, eastern-tailed blue, hoary edge and wild indigo dusky wing butterflies.

• Northern sea oats (Chasmanthium latifolium) hosts the pepper and salt skippers, Bells Rd side skipper and bronzed roadside skipper butterflies.

• Fennel (Foeniculum vulgare) besides being tasty to humans, hosts the black swallowtail butterfly. It blooms in the fall and summer.

• Surprise! Did you know the common blue violet (Viola sororia), also a spring nectar source, is a host plant for the great spangled fritillary butterfly? So before this sweet flower is berated as a nuisance, think of the beautiful butterflies.

• Goldenrod (Solidago rugosa) hosts the Baltimore checkerspot. Note that these flowers have different bloom times from spring to late fall to accommodate all kinds of pollinators.

There are other interesting host plants we see in our lawns and forest. Even though this is not an extensive list, here are a few more examples:

• Paw paw (Asimina triloba) hosts the Zebra swallowtail.

• River birch (Betula nigra) hosts, among others, the Eastern Tiger Swallow tail as does the Tulip poplar (Liriodendron tulipifera). The tulip is also a host for the tulip tree silkmoth.

• Pink turtle head (Che-lone lyonii) hosts the Baltimore Checkerspot.

• Plantain (Plantago spp) hosts the Common Buckeye.

• Here’s a fun one: Blueberry (Vaccinium spp) hosts those tiny blue Spring Azures.

• American willow (Salix discolor) hosts, among others, the Viceroy butterfly — a very excellent imitator of the Monarch butterfly.

Remember the butterflies as we cultivate and care for our lawns and gardens. Avoiding the use of insecticides, pesticides and herbicides will help save these lovely creatures!

There are a multitude of websites for further information. Just type in “butterfly host plants” and you could sit for a long time reading all about it!

(The Gardens of Silvermont, behind Silvermont mansion, are staffed by working Master Gardener Volunteers each Thursday from 9-11 a.m. They welcome visitors and are happy to answer questions. This year, Gardening Clinics will be held at the Transylvania Farmers’ Market on the first and third Saturday mornings each month. Also, suggestions for articles on gardening topics can be sent to Note “Article Idea” in the subject line).

Gardening Tasks

For October

• Plant trees, evergreens, shrubs and ground covers.

• Plant spring flowering bulbs late in month. Incorporate bonemeal and 1 tsp. of 10-10-10 per sq. ft. in rooting area.

• Plant seeds of hardy annuals: larkspur, poppy, Drummon phlox, sweet peas, coneflower, etc.

• Plant and divide flowering perennials.

• Propagate flowering shrubs by root cuttings.

• Prune out all deadwood or diseased wood from shrubs, trees and roses.

• Dig dahlia, canna, caladium, gladiolus and tuberous begonia about the time of the first killing frost. Store in cool dry place in basement.

• Repot amaryllis bulbs.

• Take soil test samples. Test boxes are available at N.C. Cooperative Extension Office, 98 East Morgan Street.


Powered by ROAR Online Publication Software from Lions Light Corporation
© Copyright 2017