Gardening chat - October 5, 2006

Carol_Stocker: Greetings Gardeners! I'm Boston Globe garden writer Carol Stocker and I will be on line live over the next hour to try to answer you gardening questions in the order in which I receive them. I will also be on line at 1 p.m. Thursday oct. 22 and Thursday Nov. 12
Carol_Stocker: My gardening articles run in the Thursday Style section. You can order my new book, The Boston Globe Illustrated New England Gardening Book from www.bostonglobestore.com for $35 including shipping and tax. It tells you what to do in the garden each week of the year in New England and includes hundreds of beautiful color photos taken by Globe photographers. It makes a great gift book for gardeners on you list and you can order a signed copy. I am also available to speak to groups and to consult on individual gardens. You can email me at c_stocker@globe.com.

lonick: My 'all summer blooming Hydrangea', only bloomed once, than did not look very good. Can I transplant it this Fall?
Carol_Stocker: You may be talking about Endless Summer or one of the other new types of colored hydrangeas that bloom on both new and old wood. This means that if the flower buds formed in the fall are killed over the winter by cold, which is what happens with most colored hydrangeas here, it will form new buds in the spring to bloom in the summer. If you planted the hydrangea this year, it may need a year to settle in and may perform better for you next year. Shrubs usually don't do much their first year and some can take five years to get good. Though shrubs are faster growing than trees, they are not as fast growing as perennials, bulbs, annuals and other types of flowers. If you think the problem is that it doesn't have enough sunlight in its current location, later this month is an ideal time to move it. The best time to move most trees and shrubs is in October after they lose their leaves. Bit of you do dig it up and move it to a sunnier spot, make sure to water it deeply after planting, and weekly after that if it doesn't rain. (But usually fall has enough rain, which makes this another good time to plant and transplant.) Another way to get more flowers next year is to completely cover the shrub with a small mountain of bark mulch. This will product the fall buds from dying over the winter if you cover the plant right to the tips of the buds. Remove the bark mulch in mid to late March. Then you will have a longer bloom period since you will have flowers from both the flower buds formed in the fall and those formed in the spring. If your hydrangea has white flowers, none of this should be necessary as white flowered hydrangeas are more winter hardy than those with colored flowers.

PatV: Hi Carol - what is the best application for bugs before bringing plants into house to winter over?
Carol_Stocker: This is indeed the time to bring houseplants back indoors. We could get a frost any night, and even if we don't get one for a while, the plants will make a better transition back to indoor life if you move them before there's a big change in temperature between indoors and outdoors. I would spray your houseplants with Safer's Insecticidal Soap a few days before bringing them indoors. Then tidy them up by removing any diseased or dead leaves.

ggentile: Is there a dwarf hydrangea that is ever blooming? I have a Nikko Blue that grows too big for the spot it is in and if I cut it back I have to wait a few seasons for more blooms
Carol_Stocker: Call Weston Nurseries at 508 435 3414. This Hopkinton nursery has the region's largest selection of shrubs and they would know about and carry any new dwarf species. There is a lot of new varieties of hydrangeas coming out and these includes several dwarfs.

Diane: We have a purple-leaf sandcherry shrub that is half dead but still has leaves througout - it has been this way a couple years but this year has been the worse. Should we just take it out or do you think we could cut it back? It is about 6-7 feet high now. 13 years old. Thanks.
Carol_Stocker: These shrubs need a lot of sun. I planted one in the shade once and it gradually died, producing fewer leaves each year. If it is 13 years old, perhaps the area has gotten shadier since you first planted it. If these seems to be the problem, this would be a good time to move it to a sunnier location. If you do this, add some perlite or green sand to the planting hole as these plants need good drainage. Don't plant it in a low area where water collects or it will drown.

newbie: Hi Carol, I have a question about what to do with the burning bushes in my yard. I didn't plant them, they were there when we moved in 2 years ago. I know ther are horrible for being invasive, etc. but what do we do? There are maybe four very large shrubs. They fill a section between by house and the neighbors, under oak trees, all mulched. I want to just hack them to bits after they lose their leaves, to at least make them smaller. If I take them out it would look so barren. What do you suggest? Get rid of them at any cost? Thanks!
Carol_Stocker: I applaud your determination to get rid of burning bush as the birds spread their berries to woodlands where they are taking over many acres of conservation land. The easiest thing would be to cut them down and then immediateply paint the fresh new cuts on top of the stumps with Round-Up. At this time of year, sap is flowing back to the roots and with luck, the Round-Up will kill the roots so they don't sprout again. The New England Wild Flower Society in Framingham recommends replacing burning bush with highbush blueberry, which grows to about the same size and likes the very acid soil you oak trees would produce through their fallen leaves. Highbush blueberry shrubs have similar brilliant red foliage in the fall, but also produce edible berries. They are not invasive and are native plants whose spring flowers attract hummingbirds and butterflies. The berries also attract a lot of birds so you'll have to put bird netting on them when the berries appear if you want any for yourself!

lettheslugs_byob: why won't my delphiniums bloom in the spring and mostly bud in the fall
Carol_Stocker: Delphiums are hard to grow. Not only to the tall types require staking, they are also such heavy feeders that they require very rich soil or die out in a couple of years unless you fertilize them a lot. They also get diseases such a black spot. When they are happy, they bloom in June and July. If you cut off the spikes of dead flowers before they go to seed, they will often send up new shoots that will bloom in October. If you planted your delphiniums this year, the fall bloom may be the first of the year, since transplanting set them back. If they survive the winter, they should bloom again next June. However, there are a lot of easier perennials with tall spikes of flowers that I would recommend over tricky and finicky delphiniums, including autumn monkshood, which blooms in October, baptisia, which bloom in June. Both come in shades of blue. Avoid lupine unless you live in norther New England as it does not survive hot summers well.

shady_lady: Hi Carol, I have a spot near my house that gets no sun most of the year, then full sun around mid-day in June and July. Most sun plants don't do well because it's too shady, and most of the shade plants I've put there get scorched. Any ideas for an herbaceous perennial?
Carol_Stocker: It sounds like you need perennials that do well both in shade and sun. Two that come to mind are Sedum Autumn Joy and Rudbeckia Goldsturm, the common perennial black-eyed Susan. You could also try hosta, foxgloves and columbine. Epimedium is an especially good plant for your situtation. Though it is slow growing, it does not require as much moisture as most other shade tolerant plants. Generally speaking, the shadier an area is, the more moisture plants need to survive, but epimedium will survive in "dry shade." Another good one to try is hellebore.

loiehayes: Hi Carol, I'm wondering about choosing trees to plant now with global warming in mind. On Mission Hill we're planning to plant ornamental fruit trees in a park. Also a row of taller trees to screen a parking garage that's being built adjacent to the park. Any advice? Thanks, Loie
Carol_Stocker: A good question! Only the toughest and most adaptable trees will survive climate change. Since a lot of these are Asian, and since Asia is the source of a scourge of new pests that will continue to come over in uninspected cargo from Global trade, I recommend Asian trees such as Asian pear trees, which I have had good luck with in my garden. They are fast growing and produce round crunchy apple like pears at a young age. They flower in April. They white flowers are pretty but have an unpleasant smell up close. You need several different kinds of cross pollination. For taller screening trees you could try zelkovia, a fast growing Asian relative of the elm tree, which is tough and disease resistant. For an evergreen screen, look for the new Pacific hybrid arborvitae Green Giant, which is also fast growing and deer resistant. Good sources for fruit trees include Fedco in Waterville, ME, one of the few places selling standards instead of dwarfs, and Roseland Nursery in Acushnet, MA.

Linda: I am looking for very early blooming shrubs, plants, trees etc to brighten the end of winter/start of spring. What would you suggest?
Carol_Stocker: If you have the space for a witchhazel shrub, which grow about 15 feet tall and just as wide, you will be well rewarded with fragrant blooms in February. Arnold's Promise is a popular variety that is a little smaller and narrower growing than most. Hellebore or Lenton Rose is the first perennial to bloom, producing flowers in February, March and April. It is slow growing and likes a shade hillside or raised bed. There are many early blooming bulbs. Snowdrops and winter aconite bloom in February, while crocus, iris reticulata and Siberian squill bloom in March. These should be planted now. My favoite crocus is Tommasianiansus because it is the first to bloom and the best spreader.

Andrea: Hi Carol ? About 10 years ago, we created a raised-bed vegetable garden that we irrigate with soaker hoses. For the first few years, we had a lot of success with our tomatoes, lettuces, peas and squash, but over the past few years, our results have become increasingly disappointing. This year, many of our seeds did not even germinate. We?ve tested the soil and the results show a pH of 6 and that the soil is deficient in potassium, nitrogen and phosphorus. What do we do next?
Carol_Stocker: It sounds like you've exhausted your soil and that it is time for some soil rehab. Also, your old soil could have acquired a lot of pathogens. I would replace it or at least mix in a lot of soil ammendments, including lime, superphosphate, finished compost, blood meal and/or green sand, mixed in to a depth of at least 6 inches. You could also try crop rotation by growing vegetables you have not previously grown and which have not therefore attracted any diseases. Some people believe you should not grow tomatoes in the same spot again until seven years have passed. So you might start a new garden for those. The best way to add nitrogen to your soil is to grow peas or a cover crop of buckwheat, alfalfa, or winter wheat, which fixes nitrogen into the soil.

dew: We have morning glory plants in pots on our eastern facing front entrance. The first year they blossomed beautifully, but the last two years they have had no flowers. Do you have any ideas how to get these plants to bloom next year?
Carol_Stocker: They are very late to bloom. I would plant varieties with a shorter growing season next year, though that would rule out the variety Heavenly Blue.

shady_lady: And thanks for the tip a few years ago abount Japanese Anemone. I've put some in and they are beautiful. One is blooming now - pink flowers with yellow centers!
Carol_Stocker: Japanese anemones are wonderful fall flowers that are underused. The best one is Honorine Jobert, but the deer ate mine this year! However they did not touch my grapleaf anemone, which has smaller pink flowers and blooms a month earlier. Everyone should try this plant. It is not quite as beautiful but much tougher than the Japanese anemone.
Carol_Stocker: That's all we have time for today. I'll be back on line Oct. 22 at 1 p.m.
Carol_Stocker: Thanks for chatting!