Ask the Master Gardener: Wait until the ground thaws to plant your lilies and gladiolus
If you would like to prolong your harvest and enjoyment of gladiolus blooms, plant some bulbs every two weeks from now until mid-June.
Dear Master Gardener: When can I plant my lily and gladiolus bulbs in the ground?
Answer: You can plant lily and gladiolus bulbs as soon as the ground is thawed and reasonably dry. If you would like to prolong your harvest and enjoyment of gladiolus blooms, plant some bulbs every two weeks from now until mid-June.
Dear Master Gardener: My young maple tree has sunscald. Should I cut out the damage?
Answer: Typically, trees will heal themselves through new growth of the inner bark or along the edges where the bark split. Sometimes it may be necessary to repair the damage. The University of Minnesota recommends the following steps for repairing sunscald damage:
- Sterilize a sharp knife by dipping it in a 10% bleach solution or soaking it in 70% alcohol for three minutes.
- Following the general shape of the wound, use the knife to remove dead bark and reveal live tissue. Round off any sharp corners to facilitate healing.
- Leave the wound uncovered. Do not apply paint, tar, or a commercial tree wound dressing to the open wound.
- Maples can be susceptible to Eutypella canker, which is caused by the fungus Eutypella parasitica. If a tree is susceptible to a fungus, spraying the area with a fungicide may help prevent fungal infection of the wound.
- Encourage good tree health and growth by fertilizing it in the spring, mulching the root area (no mulch volcano — make a ring away from the trunk!), and watering during dry weather.
- Wrap the tree in winter to prevent further sunscald.
Dear Master Gardener: I would like to plant currants or gooseberries in my garden. Will they grow here and if so, how should they be planted? Also, do I need more than one for cross-pollination?
Answer: Although currants and gooseberries are closely related, you can tell them apart by the canes and fruit. Gooseberry canes usually produce a spine at each leaf node and bear grape-sized berries singly or in groups of two or three. Currant canes do not have spines and bear 8-30 pea-sized berries in clusters. A mature currant or gooseberry shrub can produce up to four quarts of fruit annually.
Red, pink, and white currants are the same species, Ribes sativum, and are self-fertile, so one plant will set fruit without any other currant cultivar nearby. The fruit of pink and white currants is generally less acidic and is considered by some to be better for fresh eating. The European black currant is Ribes nigrum. Black currants have a strong and unusual flavor. Some cultivars are self-fertile and some are not, so if you plant the latter, you would need a second cultivar to ensure a good fruit set. Black currants are ripe when the fruit has a deep, purple-black color.
Gooseberries are self-fertile, so you will get plenty of fruit with just one plant. They have translucent skin and depending on the cultivar might be light green, pink, or even red when ripe. Remove the wilted flower that precedes the berry before eating. Then, there’s the jostaberry, which is a cross between the black currant and gooseberry. It is sweeter than the gooseberry, thornless, disease-resistant and easy to grow! It bears clusters of sweet berries with a hint of the characteristic black currant flavor. It’s hardy, heavy yielding and resistant to white pine blister rust.
Although they will tolerate partial shade, all these plants will produce more fruit in full sun. Plant them in rich, well-drained soil. Plant currants and gooseberries at least an inch deeper than they were planted in the nursery, in holes deeper and wider than their root systems. If lower canes are covered with soil to a depth of two to three buds, this will encourage a larger root system and the development of numerous renewal canes, a strategy that will maximize the useful lifespan of the plant. Plants may be spaced as close as 3 feet apart. Black currants are more vigorous and should be spaced 4 to 5 feet apart. Even though currants are generally self-fertile, research suggests that planting more than one cultivar results in better yields. You can expect to get fruit one to three years after planting.
The three recommended red currant cultivars are Red Lake, Rovada, and Honeyqueen. Red Lake was developed by the University of Minnesota in 1933, is readily available, vigorous and has deep red berries with a tangy sweet flavor. Rovada has large aromatic berries, is very reliable and resistant to powdery mildew. Honeyqueen has a long harvest period of tender juicy fruit with good flavor. The four recommended pink and white currants are Blanka, Pink Champagne, Primus and White Imperial. All but Primus are resistant to powdery mildew. Blanka has large berries with a sweet mild flavor. Pink Champagne has pink berries with very good flavor for eating, but tends to have low yields. Primus has translucent white fruit with a sweet intense flavor. White Imperial has medium sized, pinkish-white, sweet, juicy and rich-flavored berries.
The black currant cultivars recommended for northern gardens are Ben Sarek, Crandall, Crusader, and Titania. Ben Sarek has heavy yields of large berries on compact plants. It is highly resistant to white pine blister rust and is ideal for the home garden. Crandall is a cultivar of the clove currant, Ribes odoratum, and has a different, milder flavor than other black currants. It is vigorous, very resistant (maybe even immune) to blister rust, and very ornamental, with clove-scented flowers in spring and brilliant fall foliage. The canes may be weak, breaking or drooping to the ground under full crops and may need trellising.
Recommended gooseberry cultivars include Captivator, Colossal, Hinnomaki Red, Invicta, Poorman, Tixia, and Welcome (a University of Minnesota release). All are resistant to powdery mildew, with the exception of Welcome, which is moderately resistant. Poorman is an excellent choice for the home gardener, as it is vigorous with only a few small thorns, has large fruit, good flavor and ripens over a long harvest season.
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 firstname.lastname@example.org 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.