(February) My husband would like to know the best time to prune lilac and rose of Sharon.
Lilacs bloom in the spring, so the flower buds are set on them now. Prune the lilac as soon after bloom in the spring. Rose of Sharon, or althea blooms on the new seasons growth in the summer.
(February) I have a Rose of Sharon planted close to the house. It is getting very close to an eve trough and I am wondering how to shorten it. I have been cutting off the longest upright branches. Can I cut the whole bush to 12 inches or continue selective trimming?
Rose-of-Sharon is one of those forgiving plants, and can be pruned as severely or as little as you choose. Prune it by the end of the month and it should recover fine. We don't worry about severe pruning of althea or Rose-of-Sharon, because it doesn't produce attractive bark like crape myrtles. It blooms on the current growth, so prune away.
(March) I would like your advice on an althea bush I have. I moved it about two years ago and it has been so sick ever since. It is about 7 feet tall but has very few leaves that are yellow and brown and it has not bloomed much at all since it was moved. I know I don't fertilize like I should, but do you think that is what it needs. I have another one that is huge and healthy and full of blooms every year, and I don't know why this one is not doing well. It gets full sun.
I would look at the planting site. If the soil is excessively poor and rocky, or poorly drained, this could limit new growth, which in turn would limit foliage and blooms. Althea, or Rose-of-Sharon, tends to grow well in fairly ordinary soil, and even thrive in low fertility. So if it really unthrifty, I would say the site is the problem. If you really feel the site is ok, you could try pruning it hard and applying a general complete fertilizer this spring, and see if you can't generate new growth, and thus, more blooms. Sometimes too much care on altheas can result in flower buds not opening. I don't think that is the issue here, since the foliage is not thriving either. Have the soil tested for fertility levels.
(March) Can I cut back the forsythia after it blooms? And isn't it time to cut back the Rose of Sharon bushes, crepe myrtles and butterfly bushes?
Forsythia should be pruned after bloom. Remove one third of the old canes down at the soil line to encourage new growth. There is still time to prune Rose-of-Sharon, crape myrtle and butterfly bush, as all of these plants bloom on the current season growth. Try to do it soon since new growth is beginning.
(March) I have six large Althea (Rose of Sharon) bushes that are approximately 7 years old. They have been really beautiful all these years. Last year they began to get a blight or fungus and the leaves began to turn yellow. It is beginning on all of them except one. Is it too late to do anything about it, or is there something I can put on them to stop it? I really hate to lose them after all this time. I also had a Savannah Holly about 8 ft. tall and one week it was green and the next the leaves had all turned dark brown and had fallen off. It is dead I'm sure because the leaves have been gone for about 3 months. Can you tell me what happened to it? I know you would need to look at the leaves to tell, but since I don't have them, just tell me what might have caused it to do that.
Let's start with the holly. When something dies that quickly it is usually not a disease or insect problem. Was there new construction, was anything sprayed, anything change about the site? How is the drainage where all these plants are? You would need to investigate further. On the altheas, watch them this spring. If you see signs of problems, quickly take samples to your county extension office and let them send them to the disease diagnostic lab to see if they can determine any problems. In the interim, start doing some investigation on your own. Look carefully at the plants to see if there are any cracks, holes or swelling on the stems. Make sure they don't have "lawnmower and weed-eater disease". Have your soil tested, by taking a pint of soil from the area and taking it to your local county extension office. Make sure the pH is in the proper range, and that there is no salt problem. Hopefully, with careful monitoring, you can figure out what is happening and get a handle on it. It could be a disease, but it could also be insects or nutritional problems.
(July) I am inquiring about what I think is an Althea. It is not like the Rose-of-Sharon's we have. The petals aren't single with a center, the blooms look more like carnations. It is about 5 years old and has grown to about 10 feet tall and always blooms a lot (it's loaded with blooms now). It has numerous trunks, all with a diameter about the size of a quarter. The problem is this year they are all leaning to the ground. What caused this and what can I do to correct it?
I think the plant you have is still an althea or Rose-of-Sharon, you simply have a double bloom instead of a single. There are numerous varieties. If the plant has too many canes growing too close together, it can push them apart. You might try thinning the plant next February by removing up to one-third of the older larger canes at the ground line. This should alleviate any overcrowding and hopefully help to keep the stems upright.
(July) We have an althea bush that we planted several years ago. It looks very healthy, has grown quite large and every year it is loaded with buds. The problem is they never open. We have treated it for bugs and prune it every fall. What do we need to do to insure the blooms open up? It is planted on the west side of our house and gets the afternoon sun. Can you help?
First of all, we need to find out why they aren't opening before spraying with anything. Normally, altheas are tough plants with few problems, but there can be occasional plants that struggle. Cut into some of the buds. If you see tiny movement inside the bud, it could be an insect called thrips. I would find it a bit unusual, however, for none of the flowers to open, if it were thrips. Normally, thrip damage can cause distortion of the flowers, and can prevent some from opening, but unless it were a huge infestation, I would think some of them should open. If the soil is poorly drained or excessively rich, it could cause flowers to fail. While the average althea blooms with total lack of care, you will occasionally find a plant that has problems. Investigate the site and the plant, and hopefully you can solve the problem. You can also take a sample to your local extension office.
(November) On my Rose-of-Sharon plants this year, I saw lots of orange and black bugs that have been identified as assassin bugs. Now, the bugs are still there and I am wondering what they are eating? My plants did not do well this summer, and many of the buds did not open. Do you think the bugs caused this and will I need to spray next spring? If so, with what and when?
I really don't think you had or have assassin bugs. They tend to fly solo-not congregating together, and they would do no damage to a rose-of-Sharon. They tend to eat other bugs, and are actually considered beneficial. I think it is more likely that you had some other insect, possibly box elder bug, which can cause some damage. I would practice good sanitation this fall, removing the falling leaves and old mulch. Start the season off clean, and then monitor the plants. I would not recommend a preventative spray for insects, but if anything reappears, take a sample to your extension office and spray as needed.
(November) Could you please tell me if I can go ahead and trim back my Althea's that have quit blooming and also my Crepe Myrtles. With the wonderful fall, I would like to get this done now instead of February when I usually do it.
I have already seen several crape myrtles with a new "haircut" from recent pruning, but it is not our recommendation. There are two reasons I would not prune in the fall--one is that you have a cut look on the plant all winter--not as appealing to me as a full plant. Secondly, if we do have any winter weather, your plants will be more exposed to the elements. If you can, still wait until February for those plants that bloom in the summer. Keep in mind that many crape myrtles also have glorious fall foliage, that you don't want to miss out on!
Some friends gave me cuttings of their rose-of-Sharon this summer, and I have rooted them in small plastic pots. would it be better to plant them out now, or keep them over winter, taking them indoors in freezing weather, and plant them out next spring? Also, are these a hibiscus? Their flower is like hibiscus, but these are hardy shrubs.
They are in the hibiscus family. The plants would do better if they were outside during the winter, versus inside. However, they won't be extremely winter hardy. I would prepare a "nursery bed" next to the house in a protected spot. Work up the soil and sink the pot they are growing in ( or a larger container) in the soil and mulch. Water, and after the first killing frost, mulch heavier. In the spring, plant them where you want them. This way, the roots and plants should be protected for the winter, but they will go through their natural dormancy process.
Is fall a good time to trim Rose of Sharon? Also, could you suggest some drought tolerant flowers for a full sun flower bed. We've recently moved from Chicago area. Full sun has a whole different meaning in Arkansas.
While some people do prune their althea's or Rose of Sharon in the fall, the ideal time is in late February. Pruning in the fall gives you a shorn, ugly plant all winter. There is also no buffer of protection, should winter weather occur. Since they bloom on the current season growth, pruning just prior to new growth beginning is recommended. Drought tolerant flowers include annuals: lantana, periwinkle, Melampodium, threadleaf zinnia, and dusty miller. Some perennials include: butterfly weed, coreopsis, purple coneflower, daylilies, sedums, and ox-eye daisies. Mulching will help conserve moisture, and most plants do benefit from some supplemental watering --especially in summers such as this past one.
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