Ask the Master Gardener: Look for decorative lotus pods along backwater river shores

Dear Master Gardener: I would like to collect lotus seed pods for flower arrangements. I heard now is a good time to walk along lakeshores and find the ones that have washed up on shore. Where can I find them?

Contributed / Diane Froehlich

Answer: The lotus is Minnesota’s largest native wildflower bloom, with incredible 6- to 10-inch diameter pale yellow flowers. The fragrant flowers close at night and only last two days. Lotus plants are typically found in the backwaters of the Mississippi and Minnesota rivers, and some lakes in the Twin Cities area. According to Friends of the Mississippi River, the lotus was an important food source for Native Americans, as almost all the plant is edible. The unusual seed pods are often used in floral arrangements and can be found at some craft stores, although it is uncertain whether they are native lotus. In Minnesota, the American lotus is a protected wildflower — no removal of the plant is allowed. You are probably safe picking up seed pods that are unattached from the plant and have washed up on shore (unless it is private property without permission).

Dear Master Gardener: I would like to add some color to my landscape with shrubs. Is potentilla a good shrub to put in a sunny area?

Answer: Yes, it is! Although some people turn their noses up at them because they are used so much in commercial landscaping, there are many good reasons why they are in commercial landscapes. Many varieties are extremely tough, have a very long bloom period, are relatively disease and insect free, are rabbit and deer resistant, can withstand drought, and thrive in hot, open sites with full sun. Most are hardy to 50 degrees below zero. They can be used as an informal hedge or in rock gardens or as foundation plantings or in mass plantings. They do need to be pruned regularly to look their best. As stems age they produce fewer flowers, so one-third of the older stems can be cut out each year to reinvigorate the plant or all the stems can be cut to the ground every three years. Gold, white and yellow varieties retain good color during the summer heat, whereas orange, pink, and red flowers fade badly. Pink Beauty is a pink variety that holds its color best. Keep the soil evenly moist, especially the first three years as they get established. Fertilize them every spring with a 10-10-10 fertilizer.

Dear Master Gardener: I would like to put in an herb garden. What herbs are typically planted in an herb garden?

Answer: According to the Colorado State University Extension, a basic culinary garden contains garlic, chives, basil, oregano, parsley, sage, rosemary and thyme. A tea garden might have spearmint, peppermint, lemon balm, lemon verbena, chamomile and catnip. A garden for potpourri may have lavender, scented geranium, santolina and rosemary. Once established, most herbs require little water, but annual herbs and mints require a bit more water than perennial herbs.

Dear Master Gardener: I am interested in growing hops this year. What varieties do you recommend and when should they be planted?

Answer: With the popularity of beer brewing, growing hops has become very popular. The University of Minnesota hops research program has more than 16 varieties being tested at research sites in Waseca, Rosemount and Grand Rapids. The cultivars you should look for that show disease-resistance and are cold hardy are: Centennial, Nugget, Sterling and Cascade. A quick growing, gold-leafed cultivar that is very cold hardy is Aurea. The most common and economical way to obtain hops plants is by buying rhizomes (underground stems), but you can also purchase them as potted plants. Rhizomes should be planted with the buds facing up, in early spring as soon as the soil is workable. Potted plants can be planted any time throughout the growing season. Plant in full sun in soil that is well-drained and high in organic matter.

Dear Master Gardener: Are the leaves of the horseradish plant edible or poisonous?

Answer: Recipes for preparing horseradish leaves are out there, but so are warnings about their toxicity. According to Susan Mahr at the University of Wisconsin Extension, “the leaves are edible raw or cooked, but rarely eaten.” Both Montana State University Extension and Oregon State University Extension list the leaves of the horseradish plant as poisonous. According to North Carolina State University Extension, the edible parts are the roots, which are used as a condiment, but only in small amounts. Additionally, the leaves, as they expand in the spring, may be boiled in salted water until tender, then eaten with butter or margarine. They also note, “Horseradish is only toxic if large quantities are eaten.”

Horseradish plants belong to the Brassica family, so their leaves, as well as the roots, produce glucosinolates, which are the enzymes that give the roots their spicy flavor. In large amounts, these enzymes might be toxic, but in most cases, eating horseradish is safe.

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.