Invasive Plants

Did you know that out of the 50,000 introduced plants in the United States nearly 5,000 are wreaking havoc on our environment? Invasive species are second only to habitat destruction, such as by fire or land clearing, for displacing native plant and animal communities and altering entire ecosystems. They out-compete native species for food or other resources: e.g. the Japanese Barberry alters microbial activity in soils, increases soil pH, and reduces forest leaf litter. Some cause or carry disease that affects the health of native species: e.g. Hemlock Woolly Adelgid, an insect pest from Asia, kills eastern hemlock trees.

Some invasive plants have been introduced accidentally, one example is Mile-a-minute. Some species were introduced for wildlife benefits such as Multiflora Rose and Japanese Honeysuckle; or for erosion control like Japanese Knotweed; or for medicinal and/or food use such as Garlic Mustard. Others have escaped from our gardens like Purple Loosestrife, a Pennsylvania noxious invasive plant that devastates waterways.

Once they establish in natural areas their ability to propagate in several ways and to thrive in many conditions allows them to spread rapidly. Because they have few or no natural enemies in their new home they can usually out-compete native plants. This upsets the delicate balance of local ecosystems and affects the insects and pollinators dependent on the natural habitat.

Plants that are classed as a “Severe Threat” in Pennsylvania:
Tree-of-Heaven, Garlic Mustard, Porcelain Berry, Japanese Angelica, Japanese & European Barberry, Oriental Bittersweet, Poison Hemlock, Giant & Hybrid Knotweeds, Lesser Celandine, Glossy Buckthorn, Goatsrue, Giant Hogweed, Japanese Hops, Japanese Honeysuckle, Purple Loosestrife, Japanese Stiltgrass, Wavyleaf Basketgrass, Mile-a-Minute, Common Reed, Kudzu, Common Buckthorn, Jetbead, Multiflora Rose, Japanese Spiraea, Narrow-Leaved & Hybrid Cattails, Black & Pale Swallow-Worts, Bush Honeysuckles, Tartarian, Amur, Oriental Bittersweet.


Japanese barberry invades a Pennsylvania forest



What can you do?

  • Be selective and research your plants prior to purchasing them.
  • Learn to identify invasive plants and look for them on your property.
  • Remove existing invasive plants and replant or seed native plants as soon as possible.

Our Friends The Pollinators

So, what is a pollinator? Any insect, bird or animal that spreads pollen from bloom to bloom e.g. bees, butterflies, hummingbirds, wasps, moths, flies. Why do we need them? By moving male gametes in the pollen grains from the male anther of a flower to the female stigma of a flower, they bring about fertilization of the ovules. In other words, they ‘pollinate’ the female flower and seeds, a fruit or vegetable develops. Without pollination annual flowers dependent on seed production would disappear but more importantly, food production would fall drastically and catastrophically.


How to encourage pollinators into your garden:

  1. Feed them nectar and pollen. Plant a mix of trees, shrubs, perennials and annuals with a mix of flower shapes, colors and sizes that will bloom continually from early spring to late fall.
  2. It’s a good idea to have native plants at the heart of a pollinator friendly garden.
  3. Plant in groups or drifts to make the flowers easily visible to the flying pollinators.
  4. Avoid modern hybrids, especially those with “double” flowers. Plant breeders may have sacrificed the pollen and nectar to gain a showier bloom.
  5. Plant larval host plants for butterflies and moths. Many caterpillars can only feed on one or two specific host plants, particularly native trees, shrubs and perennials: e.g. Monarch caterpillars only eat milkweed, Spicebush swallowtail caterpillars feed mainly on spicebush and sassafras. Yes, the caterpillars will eat the host plant but it’s worth the sacrifice.
  6. Provide water for drinking and reproduction. You may already have a natural water source nearby, such as a pond or stream, but if not, create one. It doesn’t need to be expensive or complicated, a simple shallow dish or a dripping bottle will suffice. Be sure to change the water 2-3 times per week during warm weather when mosquitoes are breeding. A simple small solar fountain costs around $15 and will deter mosquitoes from laying.
  7. Provide shelter and nesting Sites. Bumblebees and many solitary bees nest in the ground and need open patches of bare soil. Dead wood provides nesting areas for a variety of pollinators such as some bees, wasps, beetles and ants. You can also create man-made nesting sites e.g. bee nesting blocks can be made out of an untreated wood block by drilling a number of holes approximately ¼ inches in diameter, and 3-5 inches deep. Mount the block on a post or the side of a building. An ideal place would be under the eaves of a garage or shed, which gives some protection from the rain. Pollinators also need protection for overwintering, so instead of cleaning up your gardens in the fall, wait until late spring. Perennials and grasses left standing will provide shelter and will give winter interest to your garden. Remember though, dead wood and piles of garden debris can also attract unwanted garden pests, so keep an eye on who’s living there.
  8. No pesticides! Always try a non-chemical or alternative pest control solution. Changing a gardening practice or the location of the plant can often solve the problem. If you must spray, look for less toxic options such as insecticidal soap, horticultural or Neem oil and apply them at night when bees are not foraging. At all cost avoid a systemic pesticide. These are chemicals designed to be applied to the soil and taken up by the roots, or sprayed on leaves and absorbed by the plant. Examples of their active ingredients are imidacloprid and dinotafuron. Once applied they move throughout the plant, including into pollen and nectar. While they can protect plants from certain pests, they can also hurt beneficial insects such as leaf-eating butterfly caterpillars and bees and other pollinators. See the post on how to deal with pests.

Plant in drifts


When choosing the plants a variety of shapes, sizes and colors is key.

Hummingbirds prefer red, pink, fuchsia or purple flowers. Butterflies enjoy bright colors such as yellow, orange, pink and red.

Night-blooming flowers take advantage of pollinators active at night, like moths and bats. Since they don’t see colors, these flowers are not as colorful. Instead, the flower’s fragrance attracts these pollinators.


Some plants for a sunny pollinator garden: Columbine, Butterfly Weed, Milkweed, Sunflowers, Sneezeweed, Marsh Blazing Star, Lobelia, Wild Bergamot, Lavender, Foxglove, Broad-leaved Mountain Mint, Black-eyed Susan, Blue-Stemmed Goldenrod, Smooth Aster.
Some plants for a shade pollinator garden: Columbine, Jack-in-the Pulpit, Phlox, Indian Pink, White Wood Aster, Blue-stemmed Goldenrod, Canada Violet.

Hanging Baskets

Glorious Summer Hanging Baskets


Year after year The Greenhouse produces simply the finest hanging baskets. Packed full of compatible plants and brimming with flowers, the $25 price tag is unbeatable.




What makes our baskets the best?

  • *We start with the basket. It’s thick durable plastic that won’t split and the rim will not crack. The hangers are tough and will hold the weight of a fully laden basket. It will not fall!
  • Our baskets are large and will hold a lot of water, perfect for those long hot summer days. On the hottest days you can expect to water morning and evening but unlike the shallow and small baskets, no watering three or four times a day to stop them drying out.
  • We pack the baskets with lightweight compost full of nutrients to give your plants the best start in life. While growing in the most perfect of conditions, we continue to feed them so you know they’ll reach their full blooming potential.
  • We only use the best healthy vigorous  plants and our mixed baskets are grouped for perfect compatibility. Not just color! We carefully consider the foliage and growing needs. Ask where your basket will thrive: Full sun/partial sun/shade.

Care Of Your Basket

  1. Pick the basket to suit the location and check safety of the hook/hanger
  2. Don’t let the basket dry out, check it at least daily to see if it needs water
  3. Deadhead the flowers
  4. Fertilize it
  5. Keep an eye on the weather
  6. Enjoy!

In other words: You’ve picked the most gorgeous basket and you’ve checked it will be happy where you plan to hang it. Now what?

  • Get it home safely. Make sure it doesn’t tip in the car. Hang it if possible.
  • Safety first. Make sure your hook is secure enough to hold the weight. A fully watered basket will be heavy!
  • Watering. Your basket contains closely spaced plants and their roots grow quickly. Crowded and thirsty roots need frequent watering, especially during the summer. It’s advisable to  check your baskets daily and on hot sunny days it may be necessary to water more than once a day.
  • Popping a finger into the compost is a great test of how dry it is but also get to know the weight of the basket. Your compost may have dried out on the surface but the roots might still be sitting in moist compost. A heavy basket is a happy basket. 
  • It’s not only sun that will dry out your basket. A breeze will draw moisture from the leaves and the plant will drink more; even on a cool day. If you expect a breezy day some extra water will also weight down your basket and stop it swinging. If its going to be exceptionally windy, bring in the basket as the hanging foliage will suffer.
  • Try not to let the soil dry out completely. It will cause the plant to wilt, the compost to separate from the sides of the basket making it difficult to water. If this happens place the basket in a tub of water for just a couple of hours (long periods in standing water may cause root rot) so water is absorbed slowly from the bottom of the container. Once fully moist hang it back up and hope that your plants recover.
  • Fertilize your basket to maximize blooming potential. We’ve given them a great start but the compost will run out of nutrients. Water soluble fertilizers or slow release granular fertilizers with a 1:2:1 ratio of nitrogen, phosphorus, and potassium are ideal. Fertilizers that are high in nitrogen should be avoided as they cause excessive vegetative growth at the expense of flowers. Always remember to read and follow the label directions carefully to apply appropriate amounts of fertilizer.
  • Deadheading (the removal of dead or dying flowers) larger blooming plants like petunia and geranium, prevents seed from forming and will help keep plants in bloom throughout the season.

*The Greenhouse is considering a program that will allow you to recycle your empty basket and receive a discount on next years planted basket. More information will be posted on the website and Facebook page when available.