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Extension experts identifies a plant sample for a client; photo by Edwin Remsberg

Ask the UMaine Extension gardening experts!

With years of experience in home horticulture and commercial agriculture, our experts help beginning gardeners achieve successful harvests, encourage gardeners and commercial farmers to donate excess produce to those in need, and use gardening as a vehicle to develop communities.

If you have a question about growing vegetables and fruit in Maine, you are welcome to

2020 Q&A

Answers are provided by Donna Coffin, Extension Professor, Penobscot & Piscataquis Counties; Caragh Fitzgerald, Associate Extension Professor, Agriculture, UMaine Extension Kennebec County; Kate Garland, Horticultural Professional, UMaine Extension Penobscot County; Pamela Hargest, Horticulture Professional, UMaine Etension Cumberland County; Kathy Hopkins, Extension Educator, UMaine Extension Somerset County; Tori Jackson, Extension Educator: Agriculture and Natural Resources, UMaine Extension Androscoggin and Sagadahoc Counties; Kathleen McNerney, Home Horticultural Coordinator, UMaine Extension Cumberland County; Marjorie Peronto, Extension Educator, UMaine Extension Hancock and Washington Counties; Elizabeth Stanley, Horticulture Community Education Assistant, UMaine Extension Knox, Lincoln, and Waldo Counties; and Frank Wertheim, Extension Educator, Agriculture/Horticulture, UMaine Extension York County.

Q: How can I grow Ilex verticillata (winterberry) from the berry (seed)?

A: In answer to your question about growing Winterberry, Ilex vertillata, you can use the berries from current plants.  If the berries are still firm enough, put them in a plastic bag and let them ferment.  When soft enough (might take a week) to squish, separate the clean seed.   Place the seeds in a pot, it is pretty tolerant of soils but it does grow in acidic soils in nature.  Sprinkle sand (builders sand is best) over the top to cover.  Place the pot(s) outside, it will need about 6 weeks of cold temperatures, out of direct sun so it doesn’t dry out.  This a very slow growing shrub, and it may take until the following Spring before a new shoot appears.

For more information to keep in mind about adding Winterberry to your landscape read, Native Trees and Shrubs for Maine Landscapes: Winterberry (Ilex vertillata).

Q: I have well established vegetable garden beds, but am planning an extended trip this summer. I would like to plant a cover crop that can be turned over for green manure. Which plant do you recommend?

A: If you are leaving over the summer you will want to plant a crop that does well in the heat. One that does well in summer, is suitable for a home gardener and is a great weed competitor is buckwheat. Buckwheat will flower in about 6-7 weeks after seeding. It should be plowed or tilled in while flowering and before setting seed, because then you would be fighting it as a weed species the following year. So if you are going to be gone longer than that you may want to have someone till it in and follow that with a crop of oats. The oats would winter kill and you will have a nice dead mass to work with the following spring.

This Home Garden Cover Crop fact sheet will give you a broad idea of strategy to plan to meet your needs for the length of time you will be gone.

Q: I live on about three acres and had a dog until about a year ago. There was a portion of the yard in the back that we let grow up into a field and when I would go about cleaning feces out of the yard I would throw it in that field off and on. This past year we mowed the entire area. We never cleaned the area, but kept it mowed and I didn’t throw any dog feces in the area. At present there is no dog feces present (just the occasional deer/random wild animal feces). I was wondering if that spot would be okay to use for our garden this spring or if the soil is now contaminated and unusable?

A: Since it has been a year since you have placed any of the dog’s waste in the field you wish to establish a garden in, it would be completely safe. By now any feces remains and associated pathogens should be well decomposed. The soil and its associated microbial life are excellent filters and decomposers. Our general guidelines for when animal/dog waste is found in farm and garden fields is to remove the waste and not to harvest vegetables or fruit that were in contact with it. With establishing a new garden now there would not be any remaining risk.

Q: I am looking for a reliable source for Russian Comfrey. Do you have any suggestions?

A: While I am not familiar with herbalists in the Freeport area who may carry it, there are several very good nursery/greenhouses in your region that should carry Russian Comfrey, which you can find from this comprehensive list of Nurseries and Garden Centers in Maine.

Q: I am new to Maine and building a new home in Damariscotta. I am installing a septic tank and leach field. I know not to plant woody plants, trees or vegetables. But what should I plant? What grass types are best for this region? Are wildflowers okay?

A: As our UMaine Extension fact sheet on Gardens and Septic Systems states, turf grasses are best suited for planting over a septic field. Any of the cool season grass mixes you would find in local garden centers would be suitable.

While wildflower mixes would also be generally suitable, you should avoid deep-rooted woody perennials that could potentially clog up pipes, and also be aware that wildflower natural areas are not easy to establish. Check the Native Plant Trust (formerly New England Wildflower Society) for a list of suitable wildflowers for New England and planting instructions.

Q: My Winterberry bushes are getting leggy and tall. I would love to have them bush out more from the bottom, grow thicker. Can Winterberry be cut back hard? When is the best time to do it, if so?

Photo by Richard Webb,

A: The natural habit of our native winterberry when it grows in the wild is quite leggy and open. When pruning, the objective is to enhance its natural habit rather than try to force it to be more bushy. Remove crossing, rubbing branches, and growth that is directed inward across the center of the plant. The goal is to obtain good air circulation and sunlight penetration throughout the shrub so that you will minimize disease and maximize flowering and fruiting. In my own experience, when I have cut winterberry back HARD to stimulate new growth, it has been quite slow to recover. Winterberries do not send out copious amounts of new shoots each year. If the plants are in full sun, they tend to send out more new growth each year than if they are in the shade. Some cultivars have a rounded habit and others are more open and broadly spreading.

There are dwarf cultivars (Red Sprite (female) paired with Jim Dandy (male)) that are more dense in habit than the straight species. If you want more visual impact from your winterberry planting, consider planting a drift of several shrubs together.

Q: A neighbor just brought me a Magnolia branch that broke off his tree. We live in Cushing, Maine. Can you advise me on what I need to do with this clipping/branch in order to plant it in the Spring?

magnolia blossom
Magnolia blossom. Photo by C. Eves-Thomas.

A: It sounds like the branch which broke off would be considered a hardwood cutting (that is a dormant, mature stem). The best type of cutting for rooting a magnolia would be considered a semi-hardwood cutting (partially mature wood of the current season’s growth, just after a flush of growth).

Having said that you can certainly give it a try.

Where it has broken off cut it again with a pruning clipper to get a nice straight clean cut at the bottom. You should dip the end in a rooting hormone which can be purchased at a local garden center. Then place the cutting in a plastic bag with some moist (not soaking) sphagnum moss or wood chips and place it in your refrigerator for the winter. In spring bury the cutting in your garden such that only the top few inches of the growing point are exposed.

A second method would be to treat the cutting with a rooting hormone as suggested above, and place it in a flower pot with vermiculite as your rooting medium. Well-drained potting soil can also be tried if that is what you have on hand. Moisten the medium well and place the pot and cutting in a plastic bag. Keep it in bright light but try to avoid direct sun and make sure it stays moist until rooting has occurred.

A more detailed description can be found in this fact sheet from North Carolina State University on Plant Propagation by Stem Cuttings.

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