Gardening in Larimer County

Gardening is a wonderful way to experience nature and spend quality time with children.  Youngsters love to explore the world around them.  They see the vibrant colors and  smell the intoxicating aromas of flowers.  They feel the different textures and taste the bountiful varieties of fruits, vegetables and greens. Parents and caretakers need to be aware that among the beauty, there can be hidden hazards to children and pets within plants in the home and garden.

Very young children explore their world and learn by putting things in their mouth.  They are naturally drawn to pretty flowers, foliage, and berries. Children need to be taught from an early age that not all plants are edible.  Some, if ingested, can lead into mild or moderate illness and some can potentially be fatal.  You cannot tell by looking at a plant whether or not it is poisonous.  In some plants only certain parts of the plant contain toxins.  Well known examples are potatoes and tomatoes where the vines and foliage contain toxins.  Rhubarb is another example where the stalk is edible, but the leaf is toxic. The toxicity of a plant is based on many factors including growing conditions, season, amount ingested, and age and size of person ingesting the plant.

The following list of plants which are potentially toxic if eaten is taken from The Hidden Hazards in House and Garden Plants by Spoerke, Evans, and Linaburg, 1991: jequirity bean (seed), baneberry (seed, root, berries), monkshood (all parts), horse chestnut (leaves, nut, fruit), buckeye (leaves, nut, fruit), fools parsley (all parts), yellow allamanda (all parts), belladona lily (bulb), Japanese anemone (all parts), betel nut (nut), wolf’s bane (all parts), deadly nightshade (all parts), Japanese laurel (all parts), angel’s trumpet (all parts), bird of paradise bush (seeds), marsh marigold (foliage), viny bittersweet (foliage), night jessamine (seed, fruit), water hemlock (all parts), virgin’s bower (all parts), kaffir lily (bulb), larkspur (foliage,seed), autumn crocus (all parts), hemlock (all parts), lily of the valley (leaves, fruit, seed), morning glory (seed), Scotch broom (foliage), daphne (all parts), jimson weed (all parts), delphinium (fruit, foliage), foxglove (all parts), pigeon berry (berry), wahoo (leaf, bark, fruit), spindle tree (leaf, bark, fruit), Carolina jessamine (all parts), glory lily (all parts), heliotrope (foliage), hyacinth (bulb), spider lily (bulb), henbane (all parts), English holly (bulb), American holly (bulb), yaupon (berry), jicamilla (seed), mountain laurel (all parts), coyotillo (fruit), golden chain tree (seed), lantana (unripe fruit), white osler (leaf, flower), privet (seed), cardinal flower (all parts), tomato (foliage), Chinaberry tree (fruit), moonseed (root, fruit), daffodil (bulb), oleander (all parts), tree tobacco (all parts), wild tobacco (all parts), star of Bethlehem (all parts), American mistletoe (berry), pokeweed (all parts), buttercups (foliage), azalea (all parts), castor bean (seed), black locust (seed), elderberry (seed, bark), bloodroot (sap, rhizomes), sedum (all parts), bittersweet (all parts), eggplant (foliage), Jerusalem cherry (leaf, unripe fruit), potato (leaf, sprouts), tansy (leaf, flower), Japanese yew (leaf, seed),yellow oleander (all parts), tulips (bulb), Indian poke (rhizomes), wisteria (seed), death camas (bulb).  These plants should be kept out of the reach of young children.

Household pets and farm animals are also at risk for plant poisoning.  Small amounts of onion can prove to be fatal to a dog.  Cats are particularly susceptible to poisoning from daffodils and Easter lillies.  Household plants that are a common problem to animals include philodendron, dieffenbachia, cyclamen, corn stalk plant, sago palm, and bird of paradise.  Plants that are poisonous to horses include larkspur, locoweed, lupine, milkweed, Russian knapweed, yellow star thistle and buttercup.   These plants tend to be problematic where overgrazing has occurred.

More than 700 plants are toxic to some degree.  Most cases of plant poisoning occur in children under the age of 6 and in pets.  The best way to prevent poisoning is to keep potentially harmful plants, bulbs, and seeds out of the reach of children and pets or remove them completely from your environment.  Learn to identify  the plants in your environment to know if a potential problem exists. Teach children not to touch, chew on, taste, or eat any part of a plant or mushroom unless they are known to be safe.  Eat only plants from known sources.

If you suspect that your child or pet has eaten a poisonous plant call your doctor or Colorado Poison Control at 1-800-332-3073. Keep a complete sample of the suspected plant including stem, leaves, flower, and berries or fruit for identification by a horticulturist or plant authority.

For further information see fact sheet #7.237 - Edible Flowers

Question:   I see small brown and gray moths in my house.  What are they and how do I get rid of them?

Answer:  What you see could be Indian meal moths.  The immature moths will feed on any dry food source including nuts, grains, dried fruits, cereals, dog food, and birdseed.  The way to get rid of them is to search all possible sources of food for small white worms and webbing. Then, place the infested food package in the freezer for several days.  This will kill the larvae.  Placing the infested food in the oven at 125 to 130 degrees for three hours will also work.  The best way to prevent further infestation is to place all possible food sources in tightly sealed containers.

Question:  I have seen webbing and small white flecks on the leaves of my houseplant.  Have I got spiders in my plant?

Answer:  What you have is spider mites. They feed on the sap of the plant. Spraying the plant with water once a week in the sink or shower can help to remove the mites.  The use of an insecticidal soap can also be helpful.

Question:  I had problems last year about this time with large annoying flies coming into my house.  How can I stop them this year?

Answer:  What you experienced were probably cluster flies.  In late summer they enter houses seeking shelter to overwinter.  They enter through cracks and openings in buildings then move to upper stories to form large aggregations.  Prevention is the key to control.  Caulk or cover all openings in the home, now, to prevent flies from entering before they become a problem.

Look to ornamental grasses to add interest to your landscape.  There are grasses that do well in dry conditions such as Indian grass and prairie dropseed.  Grasses that do well in moist conditions include moor grass and Japanese blood grass.  When planning to add ornamental grasses to your yard, check to see if they do best in warm temperatures or in cooler temperatures.  This will help you make the best selection for your garden's location.

Try to include edible flowers into your landscape.  These include marigolds, calendula, and nasturtiums.  Flowers can be used in many recipes.  Roses for example can be used in flavored vinegar, flavored butters and tea.  Petals can be candied and used to decorate cakes.  Don't spray with pesticides if you are growing flowers for consumption.  Keep in mind that some flowers are poisonous.

When you buy tomato plants in the spring, you'll notice that the label will specify "determinate" or "indeterminate."   Knowing the difference can help you plan your harvest.  Determinate means that the plant will grow to a given height and then put its energy into producing a crop.  Celebrity is a variety that you can grow if you want a large crop all at once for preserving.  Indeterminate tomatoes grow and produce until frost.  They might need to be pinched back to keep them under control.  If you want salad tomatoes all season, then these are the tomato varieties to look for.

The authors have received training through Colorado State University Cooperative Extension's Master Gardener program and is a Master Gardener volunteer for Larimer County.

Gardening and Insect Fact Sheets are available on-line by clicking HERE.

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This page updated:  March 28, 2003