Dear Master Gardener: Someone told me you can cut peonies, put them in the refrigerator, then take them out months later for a bouquet. Is it true?

Answer: Yes, it is true, but it depends on the variety. In addition, knowing when to cut and properly store them is crucial to having them open at a later date. To store peony flowers for later bloom you need to cut the flowers when the buds show some color and are soft like a marshmallow. According to Michigan State University Extension, once the peonies are cut, store them dry. They suggest stripping the leaves off the stem to reduce water loss. Then, wrap the peonies completely from cut-end up and over the bud in clear plastic wrap, sealing both ends of the wrap. A tight seal is imperative if you are storing them in a frost-free refrigerator. Store them horizontally for up to three months. When you remove them from cold storage, cut the stems and place them in tepid water in a cool area. Once the peony is hydrated, it should bloom for about one week.

To store peony flowers for later bloom you need to cut the flowers when the buds show some color and are soft like a marshmallow.
Contributed / Jennifer Knutson
To store peony flowers for later bloom you need to cut the flowers when the buds show some color and are soft like a marshmallow. Contributed / Jennifer Knutson

Dear Master Gardener: My neighbor picked a few berries off his jack-in-the-pulpits and asked if I wanted to try one. I declined. Are they edible?

Answer: No! Jack-in-the-pulpit plants bear small, cylindrical clusters of green berries, which grow larger as the season progresses. The green berries turn orange in August or early September then ripen to a brilliant red. According to Michigan State University Extension, the berries are poisonous and cause intense irritation and burning if put into the mouth. It’s wise to never try berries while hiking (or visiting a neighbor’s garden) unless you can positively identify the plant and know that the berries are edible.

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Related: Ask the Master Gardener: Don’t take down those hummingbird feeders just yet

Dear Master Gardener: Some sections of my lawn seem to be mostly creeping Charlie. How do I eradicate it?

Answer: Creeping Charlie is an aggressive, problem weed with one redeeming quality — it attracts and provides food for pollinators. It’s in the mint family and, like all plants in that family, it spreads by stolons (surface roots) and will regrow from very small pieces left behind in the soil. To discourage it from growing in the first place it is important to have a healthy, vigorous lawn. Proper selection of grass varieties for your site, fertilization and good watering practices will encourage deeply rooted grasses that can out-compete weeds. Most lawns are made up of Kentucky bluegrass and perennial ryegrass and need full sun. As shade increases, it becomes more difficult to sustain a lawn and more favorable for weeds like creeping Charlie.

Related: Ask the Master Gardener: Add water when clematis plants are browning from the bottom up

The key to successful control of broadleaf weeds such as creeping Charlie, dandelions and plantain is in the timing and proper application of an herbicide. September is the best time of year to control broadleaf weeds in your lawn. If more than 50% of your lawn is creeping Charlie, you may want to consider killing the entire area with a product containing glyphosate and then reseeding. Keep in mind you will be killing all plants including lawn grasses. You can usually reseed within a few days after application. If you want to treat a small area, you can use a systemic, selective broadleaf herbicide that contains 2,4-D, Dicamba, or triclopyr. Triclopyr will be the most effective for creeping Charlie. If applied properly, these products will not kill lawn grasses and usually only require two to three applications per year. Read and follow all instructions and guidelines on the label of any product, synthetic or organic, including proper clean up and storage. The herbicide label is the law.

In the past, borax was recommended for eradicating creeping Charlie, but research has shown that adding boron to the soil, even in very small quantities, can create an unfavorable growing environment making it difficult to re-establish lawn grass. In addition, and most importantly, it is an illegal application.

Related: Ask the Master Gardener: Oleanders can be houseplants, but be wary of their toxicity

Mid to End of September Gardening Tips

  • Now is a good time to plant evergreens. Smaller plants are easier to plant and become established more quickly than larger ones. Mulch over the roots with three to four inches of shredded bark or wood chips, pulled back an inch or so from the trunks to allow for air circulation. Watering is critical! Water weekly unless there is enough rainfall, and continue to do so until both the mulch and soil freeze.

  • Plant spring blooming bulbs such as tulips, daffodils, grape hyacinth, snowdrops, and scilla from mid-September through mid-October.

  • Bring amaryllis bulbs indoors before a frost, and place them in a dark, cool place to rest in preparation for winter bloom.

  • Cure winter squash and pumpkins in a warm room for ten days to toughen the skin. Store at 50-55 degrees for up to several months.

  • Pick apples when the fruit easily twists off the branch without breaking the spur or branch. Pick plums when they are fully ripe to get the best flavor.

  • Pick grapes as they reach maturity using taste as your guide. Taste-test a grape every few days and harvest the clusters once they are sweet enough for your liking and have lost their tartness.

  • Harvest eggplants when they are six to eight inches long and glossy. Use a knife or pruner to cut the fruits off the plant to prevent damaging the plant.

  • Move citrus plants such as lemon, orange, or kumquat indoors for the winter. Isolate them for several weeks, checking for unwanted insects, to avoid infecting your other houseplants. Grow them in a sunny spot, as they need some direct sun for at least part of the day. Keep the leaves clean by periodically wiping them with a soft, damp cloth.

Related: Ask the Master Gardener: Gardeners experiencing common tomato disorders

You may get your garden questions answered by calling the new Master Gardener Help Line at 218-824-1068 and leaving a message. A master gardener will return your call. Or, emailing me at umnmastergardener@gmail.com and I will answer you in the column if space allows.
University of Minnesota Extension Master Gardeners are trained and certified volunteers for the University of Minnesota Extension. Information given in this column is based on university research.