Learn to Garden - Growing Roses and Perennials Made Easy
Advice on growing perennials, hybrid tea roses, old garden roses and other types of flowers. Anyone can be successful at gardening.
Flower Gardening Problems Answered
Category: General Plant Questions | Plant Diseases | Plant Pests | General Rose
General Plant Questions
Q: What types of cool-season plants will perform in partial shade and that are inexpensive? How much sunlight do they need, or can they grow in shade? If not in shade, are there any flowering winter plants that will last all season that are cheap?
A: I recommend Pansies, Violas and Petunias. Also, in November, purchase some inexpensive seed packets of Giant Imperial Larkspur (lots of them). Sow them on top of roughed up soil and they'll bloom in early Spring. Most of these plants need sun for proper blooming, but will do fine in partial shade. Now is a good time to plant the Pansies, Violas and Petunias since the weather is (or will be) cooling. When planting them, I recommend you put a touch of blood meal and/or bone meal in the planting hole with each plant. Follow the label directions. Click on the link for more information on other cool-season bedding plants for gardening zone 8.
Q: I want to divide some of my Blue Chip Campanulas, but it being the middle of September and the fact that I'm in Minnesota I'm concerned that it may be too close to winter freeze to divide them. Should I do it now or wait?
A: I recommend against dividing now. Although they would likely be fine, I would error on waiting until fall or spring after the new growth begins to form. Dividing plants now in the summer months could cause undue stress to the Campanulas. In my opinion, it is best to perform the division in the middle of fall or early spring. I recommend waiting.
Q: What chores do you perform in your garden and at what times throughout the year do you perform them?
A: I get this question quite often so I've put together a simple timeline that is specific to my gardening zone which is 8a. However, anyone in the country could use it as a guide for their own local area by simply determining the differences in time from their zone to mine. For instance, someone in the gardening zone directly above me (7 for instance) would perform garden chores about 3 to 4 weeks prior to my performing them here in 8a.
Q: Have you grown Dahlias in your area and if so were they of the expensive variety or the type you can get from Home Depot and Lowes? How did they perform?
A: In response to your question, yes, I have grown Dahlias. You can see them in my photo album and a sample is included in the photo at the right. For me they were easy to grow given the soil conditions were favorable--lots of organics, fertilizer and water. I also "side pruned" the blooms to ensure the central bud was as large as possible. They were beautiful. However, once the heat of summer began to settle in over us they began to go downhill. I was overall very pleased with their performance. In addition, I purchased mine at Lowes and Home Depot and the rhizomes were of small to medium size. I anticipated the plants and blooms would be small, but to my surprise they graced the garden with huge flowers. I will definitely plant them again next year. I don't bother with digging them up, etc. as they can be purchased for very reasonable rates.
Plant Diseases
Q: I have a white powdery substance on the leaves of several of my perennial plants. What is this and what can I do to remove it using something organic? I prefer not to use chemical sprays as I have grandchildren that frequent the area.
A: Try using about a tablespoon of baking soda and a few drops of liquid soap to about a quart of water. Spray this solution onto preferably the entire plant two times per week, especially during those warm, humid days and cool nights. This type weather is prime for Powdery Mildew spore growth. You should also make sure the shrub is getting adequate air circulation and sun. (Powdery Mildew Photo)
Plant Pests
Q: I have a woodpecker boring holes into my 10 year old live oak tree. What can I do to rid myself of this problem short of shooting them?
A: In lieu of giving you a half-baked response and since I'm not sure how to answer your question, I enlisted the help of Dr. Gary Wilson of the LSU Ag Center. He indicated that a woodpecker will typically only bore holes in trees that are already plagued by bugs. The trees do not necessarily have to be infested, but do have to contain food for the woodpeckers. Dr. Wilson indicated the birds can feel the insect's vibrations beneath the bark through their feet, and "X" marks the spot where they will begin pecking away at the tree bark. Dr. Wilson recommends treating the bugs or the source of food for the woodpecker. He specifically recommended Thionex or Permethrin for control of the wood boring insects. This should kill the insects and thus eliminate the bird's food source.
Q: Help! My Crepe Myrtles have a black, sooty substance on them, and also have tiny green bugs surrounding the majority of the new growth. What should I do?
A: If the tiny green bugs have soft bodies and are about the size of the tip of a ball point pen I would suspect aphids are the culprit. This being the case, you can produce a somewhat short term solution by blasting them off of the plant with a strong stream of water from the water hose sprayer. Once they hit the ground they will likely die. Next, I would recommend a systemic insecticide--systemic meaning the chemical stays within the plant and continues to work even after you are done spraying. Any insecticide that treats and kills aphids should work. Read the label directions as it should tell you which insects are controlled. As mentioned here, Orthene 75 WP should work great. It can be purchased online at Rosemania.com. It has systemic properties meaning the chemical will stay within the plant for several days after the initial application and will continue to control the aphid infestation. The black sooty substance mentioned is simply a mold of sorts. The aphids produce a waste product that is sticky. This sticky substance then grows the mold that is seen as the black sooty substance. There isn't really much you can do for this aesthetic attribute other than to prune off the damaged or ugly growth.
Q: I have brown streaks in my rose blooms, especially on the lighter colored blooms. What could be causing this?
A: From your description, I highly suspect Thrips, which you can read about here. I have dedicated a fairly large portion of my content on these tiny, near microscopic critters and have included a photo of a rose bloom with thrip damage. Unfortunately, in my opinion the only way to control these pests is with chemicals. I have found that spraying preventively is very productive.
General Rose
Q: We have four mature rose bushes in front of the house we bought last Spring. Two of them are LARGE hybrid teas (I think). They are gorgeous and have bloomed very well. My problem is they are much too large for the space they've been given. The largest is about ten feet tall and easily fifteen to twenty feet around. I know to wait till it's dormant to move it, but please tell me how much to cut it back and, because it has only three to four feet of open ground - it is between our porch and our sidewalk - how am I to get enough root to keep it safe?
A: If I lived in your gardening zone and based on the information you've provided, I would recommend the rose bushes (which sound like some form of climbing or shrub rose) be cut back to about 3 or 4 feet above the ground. When cutting, go ahead and cut several of the lateral canes and twiggy growth and any dead wood out of the plant. Next, I would dig out around the root ball about 2 or 3 feet and down about 2 feet being careful to do as little damage as possible to the roots. You're going to have to make clean cuts with a shovel and perhaps some loppers (big prunning clippers) to sever the roots. The goal is to retrieve the root ball (about 2 ft squared) keeping the soil in tact. It might help to wrap the root ball in a potato sack or burlap sack until you're ready to put it in its new home. Next, I would dig the new hole and ensure it has adequate drainage. You can ammend the new hole with some form of organic fertilizer at the time of planting, water well and you should be home free with your newly located rose bush. It might help, too, if you watered the first few times in the spring with a root stimulator, which can be purchased at your local nursery or home supply store.
Q: I recently bought two rose bushes and do not know when is a good time to plant them in the ground? I had 23, mostly hybrids, but have lost a few and don't want to loose anymore. Please help.
A: Most any gardening literature found on transplanting roses indicates you should take this action only when the plants are dormant (i.e. in the winter months such as February). I, too, agree with this literature. Since we are into the fall months and the temperatures are cooler, I would likely proceed with planting the rose bush now. I would follow this with consistent watering and a thick layer of good mulch. One other option you might take would be to store the bushes out of north facing wind and perhaps in a lighted store room to protect from winter's cold. The problem with purchasing roses now is that they have no time to establish themselves before winter. Thus, why it may work better for you to keep them in their containers and store until February. Either way, there is a small risk that they may not make it, but I would worry too much about that. They will likely do just fine. And one last note...do not fertilize them until you begin to see new growth in the spring. Simply keep the canes and roots moist during winter and the crown mulched very well.
Q: How should I plant a Lady Banks rose and what are the key care instructions for achieving success with this bush?
A: The climber should be planted in full sun, although some shade shouldn't be a probblem other than possibly reducing the number of blooms. I would recommend planting it in February or March followed by a good watering. Next, mulch well. I would also recommend you fertilize with an all purpose fertilizer sometime in the early spring or just before the last frost for your area. I would ensure it has adequate drainage and about 1/3 organic material or rotted and composted manures. You could also use rotted cotten seed hulls or rice hulls or basically anything that rots and is well composted. For the remainder use 1/3 sandy loam and 1/3 topsoil. Worse case, just mix some organics into your existing soil and you should be okay. Be sure to water well the first season, especially in the hottest part of the season so that the climbing rose can become well established. After that, you can lay off of the pampering as it should do fine as an adult plant with fairly infrequent watering, except of course during our July and August weather here in the south.
Q: I was looking at a list of climbing roses a store has available. In some of the descriptions it states "a deciduous broad leaf rose." I know what deciduous is, but what is a broad leaf rose?
A: I'm sure you are aware that the term "broad" simply means wide or the opposite of "narrow" or "skinny". For instance, you've probably heard the chemical weed control producers on the market advertise that their product kills many types of "broad leaf" weeds. This simply means that it kills vegetation that has broad leaves or wide leaves (this is why you can't apply those products near your roses because it'll kill or damage them too). The opposite of a broad leaf weed would be grass as a blade of grass is very narrow--not broad. So, how does this relate to your question? Simply put, a broad leaf rose is a one that has broad leaves or wide leaves as measured from one side of the leaf margin to the other. There exists some rose varieties that have extremely "skinny" or very narrow leaflets. Then there are many varieties of roses that have wide or broad leaves and some of those do include hybrid teas, floribundas, and as in your case climbing roses. This would indicate that the climbing rose you are interested in purchasing will have wide or broad leaves rather than very narrow leaves. And as you pointed out in your inquiry the term "deciduous" just means that during the fall and winter the shrub or rose will loose its leaves. I hope this helped answer your question. If not, please submit more questions by clicking the contact me navigation at the top of any page throughout this website.
Q: Last summer and now this summer my knock out roses developed a scalded look; the leaves and buds are small and burnt looking. I cut away the problem last fall and this spring they were so gorgeous so I increased their number to 21 bushes. Super phosphate was a wonder in the spring but now the roses are scalded looking again. I've sprayed several times for insects but would a fungicide be the cure?
A: Although I have never experienced your problem with growing Knockout roses I do have a friend that experienced what you describe. They also grow several Hybrid Tea roses, and when spraying them for insects and disease they would also spray their knockout bushes. Doing this "fried" them just as you describe. I grow a handful of these earth kind roses and also grow near 100 hybrid tea roses. Although I spray the hybrid teas frequently, I purposely avoid the knockouts for the belief that they not only are earth kind and do not need spraying they despise it. Thus, I've learned to water them somewhat to get them established and then leave them alone. As long as the soil is somewhat decent and they aren't drowning in water, they should be productive for you. They really are very tolerant of most conditions. I've even heard some people planting them in pure clay soils with fair to good results and bloom production. By the way, avoiding mine with sprays and fertilizers has resulted in awesome-looking plants and blooms two years and counting.
Q: I'm looking for a climbing rose for zone 5 that meets the following requirements: disease resistant, fragrant or sweet-smelling and repeat blooming. Can you help recommend one?
A: I have had lots of luck with the Antique Rose Emporium. They have a large selection of antique and old garden roses including climbers. The only concern with some of these noted below is their disease resistancy--you may have to use some preventative measures, but for the most part you should be okay. I'm including direct links to the following that I favor for your zone:
Albertine - Large Flowering; fragrant; height to 18 feet
Arrillaga - Large Blooms; fragrant; height 4 to 6 feet
Awakening - Large Flowering; fragrant; height to 20 feet
Blossomtime - Large Flowering; fragrant; height 6 to 8 feet
Iceberg - Climbing Version of Iceberg; fragrant; height 8 to 10 feet
New Dawn - Large flowering, fragrant, height to 20 feet (highly recommended)
Click here to send your questions, and I'll do my best to help you answer them here or logon to our forums to ask other gardeners for advice. Have a photo of your problem? Even better! . . . send it direct to me by clicking here, and I'll post it on our "Problem Pics" section of the site with a proposed solution.
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