Summer is rose time, so let’s answer some of your questions about roses.
Q: My roses are dropping their leaves. They turn yellow and fall off. What can I do?
A: Take a close look at the leaves. Are they just turning yellow, or do they have some black spots on the yellow leaves?
If they are just yellow, there are several possible causes. Overwatering or just too much water around the roots due to poor drainage is one reason. Too hot of a location, especially in the afternoon, or the opposite, too much shade, will both cause leaves to turn yellow and fall off. If there isn’t enough nitrogen in the soil, the lower leaves turn yellow and drop off.
If there are black spots, the leaves are infected with a fungal disease appropriately called black spot. Leaves that stay too wet due to irrigation or rain, especially in a spot that doesn’t get much air circulation, are more likely to get black spot. Cut off any infected leaves and discard them. If you can’t change the watering or air circulation, you could try newer rose varieties that are resistant to fungal diseases, or you can spray the plants with fungicides that list black spot on the label.
Q: My new rose plant only flowered once in the spring and hasn’t bloomed since, even though the plant is growing new branches. Does it need fertilizer?
A: Maybe, but it could also be a rose that only blooms once per year. Old rose species such as the gallicas, damasks, and mosses bloom only once each summer. The flowering stems are borne on old wood. They should be pruned after they bloom. A few canes can be removed at ground level or the whole plant can be cut back by one-third to one-half. If they are grafted varieties, prune above the graft.
If you think your roses need fertilizer, follow the label directions for the rose food you purchase. Make sure not to use the fertilizer after late summer to avoid causing the rose plant to grow too much in the fall when the new growth could be damaged by a frost.
Q: I bought my wife a supposedly fragrant rose for Mother’s Day. The flowers don’t smell at all. I can’t take it back, so how do we get it to have the fragrance the catalog said it would have?
A: If you are sure the plant is the proper variety that is supposed to be fragrant, then I am sure it will be. A newly planted rose and any other rose that is under stress may not produce much fragrance. The plant uses the energy and nutrients it is producing to try to stay alive and fragrance chemicals aren’t part of that equation.
If the plant is otherwise healthy, it will produce fragrant flowers. If it is not growing well because of insects, diseases, or a bad growing environment such as not enough water or too much heat, then you will need to fix that problem first.
Q: We have a weird rose. Sometimes, the flowers are mostly pink and sometimes they are mostly yellow. This is not the same flower turning colors as it ages. It is the same plant with different colors of flowers at different times of the year. Is this common or is it something that a rose grower would like to know about?
A: Your plant is not as weird as you might hope. There are rose varieties that change flower colors based on the heat in the weather that the flower develops in. Some change rather dramatically and others have darker richer flower colors in cooler weather.
Copyright 2021 Jeff Rugg. Distributed by Creators Syndicate.