Ask the Master Gardener: Clematis Plants Hardy Enough to Grow in Brainerd – Brainerd Dispatch

Dear Master Gardener: I’m confused. I would like to plant clematis flowers and I see them growing in Brainerd’s gardens. But everything I’ve read about them says they’re not hardy in our zone 3. How can that be?

Another variant of the Clematis plant, the Vancouver Starry Night.

Contributed / Jennifer Knutson

Answer: Maybe a little information about Clematis can help you. There are three types of clematis and they differ from each other in how and when they bloom and how they are pruned. Type 1 flowers in the spring on old growth, with buds forming the year before they flower. Therefore, they should be pruned immediately after flowering and before bud formation in July. Type 1 clematis are generally not hardy to zone 3 and are not recommended for our climate. Type 2 produces flower buds on old wood (last year) and new wood (this year). It is then divided into two flowering periods (May/June on old wood and September on new wood) and continuous flowering periods (June to September). Miss Bateman and Nelly Moser are examples of Type 2 two-color clematis. These should be pruned between flushes and only lightly. Examples of continuous bloomers are Dr. Ruppel and the President. Type 3 clematis blooms on new growth and blooms continuously, from July to September. They are usually pruned to the ground each fall or early spring, leaving only the lowest buds to encourage new growth in the spring. Examples of type 3 are the very hardy and popular purple Jackmanii and Madame Julia Correvon. Type 3 clematis will likely perform best in zone 3.

Yes, many varieties of clematis are listed in zones 4-9, but many zone 4 growers do well here, especially those flowering on new wood, as buds that need to overwinter can easily freeze. . Trust your local nurseries to stock only hardy varieties. A Clematis vine requires a structure – a trellis, a fence, a post – on which to climb, although sometimes people leave some crawling on the ground as a ground cover. The old advice of growing clematis is that they like warm tops and cool feet, which means they like their tops in the sun and their roots kept cool with moisture and mulch. An eastern or southern exposure with some midday shade works well.
Clematis is Minnesota’s showiest vine with flowers ranging in size from 1 to 5 inches and comes in colors ranging from pale white and yellow to bright red and dark purple. There is even a beautiful native white clematis, Clematis virginiana (commonly known as Virgin’s Bower) for those who prefer the natives. It is aromatic, hardy to zone 3, blooms August through September, and produces attractive seed heads.

Dear Master Gardener: I was at a friend’s house and asked him about a shrub I had never seen before. He said it’s a New Jersey tea shrub. What can you tell me?

Answer: New Jersey tea (Ceanothus americanus) is a native shrub found in highland grasslands and savannahs. It is low growing and rounded in shape and usually does not exceed 2 feet in Minnesota. It is suitable for a traditional landscape, a wildlife garden or on a steep slope. If planted 2 or 3 feet apart it forms a pretty low hedge. The plant has glossy leaves and in midsummer is covered with showy clusters of white flowers. Not only are the flowers beautiful, but they attract a wide range of pollinators, including bees and butterflies. New Jersey tea thrives in rich, well-drained soil and the deep taproot makes it very drought tolerant once established. Plant it in full sun to partial sun. It blooms on new growth, like a herbaceous perennial.

On a historical note, it was very popular during the Revolutionary War period to use the leaves as a substitute for imported tea. Additionally, the Chippewas of Minnesota used the roots mixed with water to treat coughs.

Dear Master Gardener: When can I plant tuberous begonia and caladium tubers in open ground?

Answer: Tuberous begonias and caladiums are excellent plants for the shade garden and can be planted in the ground as soon as nighttime temperatures are above 50 degrees. They are very sensitive to cold temperatures. Plant tuberous begonia tubers, which are shaped like a small brown bowl with the hollow side up. For best results, plant the tubers in pots first and let them sprout before putting them in the garden. Then plant them in the garden about five inches apart and cover them with an inch of soil. Plant the tops of the caladium bulbs 1-1/2 to 2 inches below the surface with the eyes pointing up.

Dear Master Gardener: My friend had beautiful lavender flowers in her cutting garden last summer that looked like little roses. What could they be?

Answer: It looks like Eustoma, commonly called Lisianthus, which are delicate and elegant flowers that look like small roses. They are grown as an annual in Minnesota. Lisianthus hybrids are long-stemmed flowers that come in lavender, dark purple, various shades of pink, and white. They should be planted in moist, well-drained soil rich in organic matter, in full sun and in an area protected from the wind. Wait to plant them until after the last frost date (after Memorial weekend). They are very long-lasting cut flowers that can last two to three weeks in a vase. It is one of the most elegant flowers, but unfortunately one of the most difficult to grow. Buy them as plants from a garden center as they are very difficult to grow from seed and require seven months to flower. They can also be difficult to find. If you are growing Lisianthus as a cut flower, singles are better than doubles for cut flowers.

You can get your garden questions answered by calling the new Master Gardener Helpline at 218-824-1068 and leaving a message. A master gardener will call you back. Or, email me at and I’ll reply in the column if space permits.

The University of Minnesota Extension Master Gardeners are trained and certified volunteers for the University of Minnesota Extension. The information provided in this column is based on academic research.

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