My red delicious apple tree is 6 years old and never had blooms. 2 years ago I planted a golden delicious 30 ft. away from the 1 st. tree because everyone told me I needed another apple tree for it to pollinate. What is wrong with my trees?
Knox County Illinois
Hello. I took the liberty of contacting Chris Enroth, the University of Illinois Extension Educator serving Knox County. Please see his reply below. His contact info is at the end of the message; contact him directly with any further questions.
Deborah Cavanaugh-Grant, Local Food Systems and Small Farms Educator, Logan, Menard and Sangamon counties.
There are a variety of reasons why apple trees may not be flowering. Let’s run through some general reasons and then focus on what has happened locally in your area.
Apple trees must reach a certain stage of maturity before they will begin to flower and set fruit. Seedling trees will be juvenile for some time and will take many years to come into bearing.
This is related to juvenility. In general, trees on dwarfing rootstocks will flower and set fruit at an earlier age than trees on semi-dwarfing or standard rootstocks. Trees on dwarfing rootstocks may lower the year after planting while trees on standard rootstocks may take 7-10 years to begin to flower. If trees on dwarfing rootstocks were planted with the graft union below ground scion rooting will have occurred and the dwarfing influence of the rootstock will be lost.
Trees that are vegetatively vigorous will have delayed flowering compared to trees that are not so vigorous. Excessive vigor can be caused by heavy pruning, vigorous rootstocks, and too much fertilizer (particularly N). Pruning is invigorating. Trees that have been heavily pruned will produce much vegetative growth at the expense of reproductive growth. Nitrogen fertilizer also encourages vegetative growth.
Branches that are growing vertically tend to be more vegetatively vigorous than branches that are growing towards horizontal. Bending vertical branches towards horizontal in the spring will encourage flower bud formation for the following year.
Flowers that will produce the current year’s crop were initiated the previous year just after bloom. These buds must survive the winter to produce fruit. Bitter cold temperatures during mid-winter can kill flower buds resulting in no crop the following year. There are cultivar differences in susceptibility to winter temperatures.
Apple trees that produce a large crop one year will have few if any flowers and fruit the following year. Developing seeds in apples emit plant growth hormones that inhibit flower bud formation. Thinning fruit during the “on” year within three weeks following petal fall will reduce the inhibition and result in a crop the following year.
(Source Wisconsin Extension)
Locally, there are a variety of the above factors that could have played into your apple tree not flowering for the past few seasons. The primary culprit would be the intense cold winters we’ve had these past two seasons. Red Delicious apples are cold hardy to zone 5, which is where Knox County is located. Yet, our past two winters have reached minimum temperatures typical of zone 3. (Typical in northern Minnesota, but not Central Illinois.) These extreme cold snaps, or ‘polar vortexes’ as they’ve come to be known, had the potential to kill off flower buds for less hardy plants, including red delicious apple trees. Late season frosts can also play a role in killing off spring apple blossoms.
Planting another apple tree nearby will not induce flowering, but will aid in pollination. Make sure the tree has been planted with the graft union at least 2 to 3 inches above the soil. Avoid heavy applications of nitrogen fertilizer.
If you have any additional questions please feel free to contact the Knox County Extension office at 309-342-5108