Q. I have two dwarf apple trees that are four to five years old but have never produced any fruit. I fertilize them every fall. Are there other things I should be doing?
– Duane Nagel, Rensselaer, Ind.
A. Are your trees blooming? It’s not unusual for dwarf trees to need up to five years before becoming mature enough to bloom. Overfertilizing with nitrogen, a lack of sun or improper pruning may cause a lack of blooming. Apples are borne on short fruiting branches or spurs that grow on year-old wood. Prune lightly, and avoid removing many of the spurs.
If they’re blooming and still not producing fruit, you may need to add another cultivar to your planting. Most apple cultivars are at least partially self-fruitful. However, better pollination is assured by having two or more cultivars in close proximity. Call your local Extension office and request a copy of Apple Cultivars for Indiana (HO-165). It contains a chart that lists many apple cultivars in approximate order of blooming. It’s best to select a pollinator that blooms at roughly the same time as your other apples. Other reasons for a failure to bear include inadequate bee pollination and late spring freezes.
Q. I have kiwi vines on the fence bordering my vegetable garden. Two of these are very large. I planted them 15 years ago and vaguely remember them being asexual–one is enough to have fruit. They have never produced kiwi fruit. What can I do to alleviate this problem?
– G. Gazvoda, Bloomfield, Ind.
A. The Kiwi vine that produces fruit like that in the grocery is Actinidia deliciosa, and it is dioecious, meaning male and female plants are required for fruit production. Even the supposedly self-fruitful cultivars do better with a pollinator. Actinidia deliciosa probably isn’t hardy in Indiana. If the plants do survive, the flower buds would almost always be killed during winter and early spring freezes.
There is a hardier, self-fruitful kiwi vine, Actinidia arguta, but the fruits are much smaller, like large grapes. If this is the cultivar in your garden, you should have better luck. Sometimes they don’t produce for the first three to five years, but you’ve passed that hurdle. I suspect yours are both of the same gender, or they are succumbing to late spring frosts. You may want to cover them with a sheet or spun polyester blanket (available through garden catalogs or in garden centers) during frosts.
Q. My burning bush didn’t turn red this year. This is the second year in a row. What could be wrong?
– Judy Gasvoda, West Lafayette, Ind.
A. Sunlight is necessary for the brilliant red coloring of burning bush, Euonymus alatus, to appear, so trimming back any overhanging branches from nearby shrubs or trees might help. If the plants are not too large, you could transplant them to a site where they will receive full sun. If your plants already receive some sunlight, then a soil test may be the next step. Burning bush prefers a slightly acidic soil and will not color well in an alkaline soil.
Burning bush normally shows its fall color even when deficient in nutrients, so nutrient deficiency is not a likely problem. Regular fertilization is always a good idea, and it is possible that your shrubs, if severely deficient, will respond to fertilization.
Finally, some similar shrubs (not Euonymus alatus but other species) turn a pale yellow in the fall. Perhaps your shrubs are showing their true colors after all!