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Ask the Master Gardener: How to grow a crop of Job's Tears

A rosary made of the seeds of the Job's Tears plant. Photo by Jennifer Knutson1 / 2
The peony flower is Bartzella, an Intersectional Hybrid Peony (AKA an Itoh Peony). Photo by Jennifer Knutson2 / 2

Dear Master Gardener: I have made rosaries from the seeds of the plant Job's Tears, so two years ago I tried growing it in my garden. I purchased the seeds online from the same source the past two years, but did not get a crop. What should I do next summer to get a crop from the Job's Tears plant?

Answer: Job's Tears (Coix lacryma-jobi) is a plant that is native to and cultivated in south Asia. It is believed to be one of the oldest grasses grown in cultivation. Here in Minnesota the plant is grown as an annual ornamental grass. It grows best in full sun and moist, wet soil. The seeds can be planted outdoors after the last frost date, which can run anywhere from May 22 to June 1 in Crow Wing County. Speed up germination by scarifying the seeds (scraping the seeds with a file or rubbing them with sandpaper) then soaking them overnight in tepid water. Plant them approximately one-half inch deep in a warm, sunny location. Keep the seeds moist until they germinate, which may take several weeks. Seeds can also be started indoors about six to eight weeks before the last frost date by scarifying the seeds, soaking them overnight then planting them in potting soil. Keep them in a warm spot with the soil evenly moist. When the seedlings appear, keep them in a sunny window. Transplant them when the outdoor temperatures are consistently above 60 degrees.

Job's Tears grow about 3 feet tall and resemble small corn plants. As they mature, bunches of pearly, bead-like seeds emerge in a continuous string from the stalk. The seeds start out green, then turn gray and then become shiny and black. In the fall when they turn black, they are ready to harvest. It takes about 110 days from planting to harvest. The teardrop shaped seeds, which are edible, have a hard, shiny coat and a natural hole that makes them easy to string and perfect for people who make jewelry and rosaries.

Dear Master Gardener: Which trees should be pruned in the winter?

Answer: The late dormant season is best for most pruning to avoid diseases and other problems. Oaks should not be pruned from April to October, to prevent oak wilt spread. Prune honey locusts when they are still dormant in late winter to prevent stem cankers. Prune apple, crabapple, mountain ash, hawthorn and shrub cotoneasters February through early April.

Some trees have free-flowing sap that "bleeds" when pruned in late winter or early spring. To prevent this from happening, prune all maples (including box elder), butternut, walnut, birch, ironwood and blue beech after their leaves are fully expanded in late spring or early summer. Never remove more than one-third of the live foliage.

Dear Master Gardener: I was looking at plant catalogs and was enamored by the yellow tree peony. I would like to grow a yellow peony if possible. Are they rare and hard to obtain? Will they grow here?

Answer: Often the colors we can't have are the ones we want the most. Yellow peony cultivars have existed for more than a hundred years, since the tree peony was discovered. Unfortunately, tree peonies are not hardy in our zone 3. However, there are some options. Recent hybridization efforts have introduced several yellow herbaceous (garden) peonies that are hardy to zone 3. There are three hybrids available in North America, although they are expensive. "Moonrise" is a single, soft yellow peony that blooms early in the season. "Prairie Moon" is a yellow, semi-double that is hard to find. "Claire de Lune" is a cross between "M. Jules Elie" (a pink peony) and a yellow species peony.

In 1948, Toichi Itoh, a Japanese botanist, was the first person to successfully cross a tree peony with an herbaceous peony. Sadly, he died before his hybrid flowered in 1964. Four of his plants produced deep yellow, double flowers of high quality. These plants, which are called intersectional hybrid peonies or Itoh peonies, inherited the best traits of both parents. They produce flowers and foliage that are similar to tree peonies, but have the hardiness of herbaceous peonies (hardy to zone 3). They emerge later in spring than herbaceous peonies. These hybrids have a nice upright form, stand up to wind and heavy rain and are very disease resistant. They produce many enormous flowers once they are mature and the flowers last longer than standard tree peonies. About ten years ago, you could expect to pay about $1000 for an Itoh peony. Now you can find them at local nurseries for under $100. "Bartzella" is the most popular Itoh peony, a strong, yellow semi-double with a lemon fragrance. 'Garden Treasure' is a light golden yellow, semi-double with very large blossoms. 'Sequestered Sunshine' has large, bright canary yellow blossoms with showy stamens.

February Garden Tips

• Rather than buying cut flowers for Valentine's Day, consider buying a potted, flowering plant that will last longer, such as an African violet, miniature rose, orchid, cyclamen or clivia. Remember to wrap the plant well and place it in a plastic bag to trap warm air before taking it to your car.

• Roses are still the most popular cut flower for Valentine's Day giving. To make them last longer, re-cut each stem before putting them in a vase containing water and floral preservative. Keep them in a cool location, out of direct sunlight. If the water starts to look cloudy, re-cut the stems and replace the water and floral preservative.

• Mid-February is the time to sow seeds indoors for pansies, violas, wax begonias, heliotrope, and coleus. Two weeks later sow impatiens, petunias, snapdragons, vinca, and lobelia. Most flowering annuals may be started later, about eight weeks before they are transplanted outdoors. Starting them too early can result in large or leggy plants that do not transplant as well as more compact ones.

• Note areas in your landscape that could benefit from additional winter interest. In the spring consider adding plants, such as spruce, pines, junipers and fir trees. Other possibilities include ornamental grasses and other tall perennials that can hold up to snow, redtwig and yellowtwig dogwoods, and flowering crabapples that hold their fruit all winter.

• Check on dahlias, cannas, calla lilies, gladioli, tuberous begonias and other non-hardy summer bulbs you are storing over winter in the basement. It's not unusual for some to rot in storage, especially if they are kept too warm or were damaged when they were dug up in the fall. Discard any that are soft and mushy.

• Begin fertilizing houseplants once they have resumed active growth. Use a houseplant fertilizer at half strength to reduce the chance of fertilizer build-up in the soil or burning the plant.

• If you didn't get to it in the fall, prepare for the spring planting season by cleaning your garden tools. Clean off soil residue and use steel wool to remove any rust that has formed on metal surfaces. Wipe spades, rakes, pruners, shears, etc. with ethyl or isopropyl alcohol. Alcohol will not rust your equipment. Sharpen the edge of trowels and shovels with a mill file. Coat all clean, sharpened, metal blades and the heads of shovels, hoes, and rakes with a light oil.

University of Minnesota Extension Master Gardeners are trained and certified volunteers for the University of Minnesota Extension. All information given in this column is based on university research. To ask a question, call the Master Gardener Help Line at 218-454-GROW (4769) and leave a recorded message. A Master Gardener will return your call.