Shrubs - Azaleas (page 1)
Next Page
Back to Shrubs

  (January) I have a cluster of azalea bushes that are experiencing yellowing of the larger leaves first and then moving to the smaller ones. It begins with reddening of the tips and eventually turns the leaves yellow. The strange thing is that there is one bush in the cluster that seems not to be affected. To my knowledge, they have not done this in past years. My wife does put her used coffee grounds in the bed, but has been doing this for a couple of years with no adverse effect. It has been suggested they could be iron deficient or were not watered sufficiently this fall. A scratch on the bark does reveal a nice green healthy stem immediately short of the tip of the limb. What do you think?

  I think it is a natural occurrence, and has probably happened in the past, but you may not have noticed. It is common for azaleas to shed their old leaves periodically throughout the season. Some varieties shed almost all their old leaves at one time, often worrying the homeowner. This usually occurs in early winter. Look closely at the leaves that are yellowing. If they are older leaves, furthest from the tip of the branch, this is their annual shed. Larger white flowering varieties tend to yellow more dramatically every year. Red flowering forms often shed their older leaves almost unnoticeably, since they usually turn red before falling. I would not worry, unless all the leaves on a branch are yellowing and falling. Iron deficiency is not common in the dormant season. The symptoms for iron chlorosis are yellow leaves but green veins.

  (January) Could you please tell me when is the correct time to prune Azaleas and Crape Myrtles?

  Prune only if needed. Azaleas should be pruned immediately after flowering. Crape myrtles should be pruned before new growth begins--typically late February through early March.

  (January) My azaleas were devastated by lacebugs this past summer. I am considering applying an oil spray to them this winter. Is there anything else I can treat them with to prevent the damage this coming growing season?

  Lacebug damage is prevalent in Arkansas every growing season. Using a dormant oil now, can help to start the season clean, but it will do little to prevent a new attack this growing season--plus, it is hard to get thorough coverage on the underside of azalea leaves. There are several products you can use to combat the problem before and after you have them. In mid February, consider using Bayer Advanced Tree & Shrub insecticide or Merit. This product can be mixed with water and applied at the base of the plants (under the mulch). The plants absorb it through the root system and prevent the insects from attacking later in the season. It has to be applied in advance of the growing season, not when the problem occurs. One application should last the entire season for lacebug control. If the product is too pricey for you, another option is to spray with Orthene (Acephate) after bloom, and then again two weeks later -- and then monitor the plants after that. This can also serve as a preventative spray. If you can prevent the insects from getting firmly established in the beginning of the season, they will be less likely to cause severe damage. The problem is that many folks wait until August to notice the damage, and by then it is too late. Hope this helps.

  (February) Our azaleas have had a great deal of die back and winter damage this season. I doubt if they will bloom much this summer. Would it be prudent to go ahead and trim them back now so that they will retain their shape and produce new growth?

  No. Hold off and give them a chance to bloom this spring. Many have some damaged foliage, but so far, flower buds seem to be intact. After bloom, then do whatever pruning is needed to reshape. Fertilize then as well. Hopefully, they will bounce back.

  (March) I can not find the article that you had recently on azaleas. When is it that you spray for lacebugs? I believe it was in February but I can't remember. We treated them last year per your recommendation and it really help during the summer time.

  Bayer Advanced Tree and Shrub insecticide is a good soil drench to prevent lacebugs in azaleas. One application does a great job. It can be a bit pricey. Di-syston is a granular application that can also provide several months of coverage to prevent the lacebugs. Both products are systemic and are taken up by the plant and should be applied before the plants really kick in and grow. Usually mid to late February through March is ideal.

  (March) I received several azaleas and gardenias and a pot of tulips this week when my father died. When should I plant these and how? How should I care for them until planting? They will be planted in South Arkansas (El Dorado).

  For now, just treat these plants as houseplants and give them a bright sunny location, and keep them evenly moist, but don't allow them to stand in water. Plant them outdoors in mid April to early May. Of the three plants you mentioned, you will probably have the best results on the gardenias. The azaleas might survive, but there are different varieties for hardy bushes and those forced in the greenhouse. Sometimes they do fine. Give both shrubs a morning sun/afternoon shade location in an acidic, well-drained soil. The tulips are probably best enjoyed for now. Tulips don't repeat bloom well even outside, so your chances of pretty flowers after forcing, are minimal. You can try, but I don't think it is worth the effort.

  (March) We have approximately 150 salmon azaleas in our yard. When in bloom, they are breathtaking. Last summer we had a problem with insects. We sprayed and treated without results. I took a branch of one of the plants to the County Cooperative Service office and was quickly told we needed to treat for "whiteflies" and I should ask for "Orthene". We were able to get the insecticide and as instructed treated for three days. After a few days the "whiteflies" were still flying. We treated again and again and again for the three day regiment. After a few treatments we were not able to get the same treatment from the local store so I called around and found the same Orthene. When I went to purchase the insecticide, I discussed the problem with the nursery owner and was told I should treat for longer than three days, probably six to nine days regiment to get in control. We did this, we sprayed daily for nine days, again without results. Some days the plants looked good and there seemed to be fewer "whiteflies" flying, but over the course of treatment, the leaves turned brownish-red like leaves changing in the fall. I knew this should not be happening, usually the leaves are green all year. I fear that we have lost over 90% of our plants. the leaves are still brownish-red and look very unhealthy. Should I go ahead and remove the plants or wait until spring and see how they look?

  First of all, you should not have been spraying daily with Orthene. Orthene is a systemic insecticide, the plants take it up and then insects will feed on the leaves and begin to die. You will not see overnight results, but in time the insects should slow down. Weekly applications should be made, not daily. Always read and follow the label directions. I do think you may have a little toxicity in the foliage -- the mottled yellow and red foliage looks bad. However the overall bronze foliage can be normal winter color for many red and pink flowering azaleas. I would allow them an opportunity to bloom and grow this spring, before considering replacing them. The foliage should regreen. If you get insect problems again, take a more cautious approach. Somehow timing got confused. I am sure what was meant, was that you should spray a minimum of three applications -- at weekly or ten day intervals -- not daily. If the problem persists, you may have to extend the spray schedule, but again not daily. Read the label and follow that guideline. You may also want to try a different insecticide in between -- resmethrin is a good whitefly spray. Monitor your plants closely this spring, and catch any problems as they get started. Keep in mind that many gardeners take the approach that if a little is good, a lot is better, but it doesn't work that way with gardening. It is better to err on the side of too little than too much.

Next Page
Back to Shrubs