Question: I have a climbing hydrangea that gets plenty of leaves but no flowers. What am I doing wrong? It has been in the ground for three years and is planted on the north side of my house. Thanks!

Question: Our 36 year old large Rhododendron has had branches dying on it for the last 18 months. The affected section looks like it is wilting and then it dies. There is no evidence of insects or any other foreign substance on it. At this rate we’re afraid we will lose the entire plant. Can you help us diagnose the problem?

Question: I have an old (30-40 years) flowering quince that loses about 95% of its leaves in mid July every year. But, it never fails to bloom every early March and leaf out thereafter. In fact, it is in bud now and should bloom in the next couple of weeks. What could be the cause of the leaf fall? The leaves turn yellow and fall. By September there is a partial recovery.

Question: I am interested in 10 Blueberry Bushes. We live in Delmar, DE. I am interested in your opinion as to what kind and if you would be so kind to give me instructions on getting the soil ready and any other instructions there are for caring for them. Thank you very much, and love your show on Saturday.

Answer: Any of the Blueberries listed on our web site will prosper in your area. See Vaccinium. Blueberries are partially self-sterile. Be sure to choose at least 3 varieties, in any combination, for good cross-pollination. Careful varietal selection will extend the harvesting season from early to late.

Blueberries like a well-drained, light acid soil. They resent poorly drained clay soil. They do best in full sun, although they tolerate light shade. They last for decades so proper and thorough soil preparation at planting is important. Once planted, you cannot “fix-up” a poor job of soil preparation. In Delmar, Delaware your soil should be naturally acid. The acidity is the one aspect that can be fixed after planting. In fact, the soil amendments that you till in will somewhat reduce the PH so it is pointless to fine-tune the PH until after the soil is amended. As long as your unamended soil starts out at PH 6.5 or below, you are fine. If not, add iron sulphate (not aluminum sulphate) before tilling. Next spring, test your amended soil. Blueberries do best with an amended soil PH of 5-6.

I suggest planting blueberries at least 5 feet apart with 8 feet between the rows. For each plant, amend the soil by tilling in 2 buckets of coarse sand, 1 cu. foot of peat moss, 1-2 pounds of Cottonseed Meal and I pound of Kelp Meal. The tilled soil should be “puffy” and feel gritty. If not, add more peat moss and sand. Plant at ground level and mulch with 2 inches of pine mulch—needles or bark. Do not allow your blueberries to dry out until well established; in periods of drought, water deeply twice a week.

A few final thoughts:

1. Don’t allow a crop to form the first or second year. Remove the immature berries and the plants will establish much better.

2. Bare root blueberries are difficult to establish. Container grown plants do much better. (All of Carroll Gardens’ blueberries are container grown).

3. In my opinion, blueberries are the most satisfactory of all fruits the homeowner can grow—and the plants are quite handsome, especially the fall foliage. Once established, care is minimal—no spraying. The toughest job is preventing the birds from taking your crop.

Question: What potting soil do you recommend when re-potting house plants? I have been using Miracle-Gro Potting Mix and after the plant is established, it develops that white, sticky, cotton-boll-like pest or disease. Is this just a coincidence or am I using the wrong potting soil? I do not mix it with anything else -- just straight Miracle-Gro Potting Mix.  Thank you!

Answer: I recommend Fafard potting soil; but I doubt your potting soil is the problem. It sounds like you have mealy bug—an insect that moves from plant to plant. Only valuable, lightly-infested plants are worth saving. Everything else should go into the trash—pot and all. (Valuable decorative pots can be saved if thoroughly washed). All remaining infected plants should be bare rooted, submersed in (tops and roots) in insecticidal soap solution, potted in fresh soil and a new pot, and treated with systemic granules. At the first sign of re-infection, just touch the mealy bug with a q-tip dipped in rubbing alcohol.

If you are desperate, I have had some success with bare-rooting, repotting and spraying to the dripping stage with a 50-50 mix of rubbing alcohol and water. It will either severely injure the plant, kill it or cure it totally with one treatment.

In any event, be sure to thoroughly wash the surrounding surfaces: window sills, saucers, plant stands, even drapes and curtains. How much disinfection you do depends upon the severity of the infection and the proximity of the surface to the infected plants.

Question: I have enclosed a sample of my evergreen called red tip. Can you please give me some information on what I can do to treat the spots that are all over the leaves? Hearing you on the radio over the years I feel like I know you. Thank you in advance for your help.

Answer: Photinia (red tip) is almost always afflicted with leaf spot fungus—even more so in a moist year. For this reason, we refuse to sell the plant. You can control the leaf spot by spraying with Daconil 2787 as soon as the new growth begins in the spring. Continue spraying at 2 week intervals as long as the season is moist. You may have to resume spraying from early September through mid-October. Unfortunately, the process must be repeated annually.

There are so many more carefree plants. I suggest you replace the red tip with something that remains handsome with less work.

Question:  Alan, I have a large gardenia in a huge clay pot (16"). It blooms beautifully but the leaves turn yellow. I use many brewed tea bags each month as mulch. How many and how frequently does it need the tea leaves? Should I do something else? It gets Seamate each time it is watered.

Answer: Are the new (top) leaves the ones that are turning yellow or are they the oldest (lowest) ones on the branch? These are two very different situations with different causes and treatments.

Question continued:  Hi Alan, it seems to be older leaves, rather than the very new ones. It also seems to be on all parts of the plant. There are not lots and lots of yellow leaves. Some of the leaves are brownish on the ends, which I assume is lack of humidity. For the leaves that are yellow, sometimes it's just a part of the leaves and sometimes it's a whole leaf. Thanks for your e-mail.

Answer continued: I am afraid you are using too many tea bags. For a 16" pot, the contents of 6 bags sprinkled on top annually is sufficient. But, the tea leaves are not causing the yellow leaves.

Gardenias are not easy to grow inside. They like it cool and sunny with high humidity and moist, well-drained soil—a difficult combination to achieve. When they get stressed the oldest leaves turn yellow and drop off. (If the Gardenia does not get stressed, the oldest leaves will still turn yellow and drop off after 3 years). Check the undersides of the leaves for spider mites. Mites are tiny cinnamon-colored insects. Sometimes the infestation is heavy enough that you will actually see small webs. Otherwise, hold a sheet of white paper under the leaves and vigorously shake some branches. If spider mites are present, you will see them where they have fallen on the paper. They are about the size of a pin prick and will stain the paper if you run your hand across it. If mites are not the problem, I suspect your problem is either lack of humidity, or that the plant dried out once—possibly in combination with mites. Mites can be washed away with a strong spray of water to the undersides of the leaves, a good monthly preventive practice in any event.

If you put the Gardenia outside in a semi-shaded place for the summer, it will recover nicely and gather strength for next winter’s stress. Keep feeding the Seamate!