Carol_Stocker: Greetings Gardener's. I am Boston Globe garden writer Carol Stocker and I will be on line for the next hour to try to answer your gardening questions.
Steve__Guest_: I have a raised-bed garden, and over time my soil has become so depleted that I must replace it. Unfortunately, because of the configuration, I don't really have the option of rotating crops -- and I know that only compounds the depletion problem. What should I add to the soil to condition it year to year, to at least minimize the nutrient depletion?
Carol_Stocker: The best thing would be to dig out the old soil every spring and rake it into your lawn, which will greatly improve the grass, and then replace it with compost. Apple D'Or (508-229-2440)is a good source. I would get two yards and use any extra on other plant beds or, again, raked into your lawn. I would also find some Calcitic Lime (NOT the common dolomite lime sold in most garden centers) and mix this in with your vegetable garden soil and your lawn as both like lime. Calcitic lime has seven times as much calcium as magnesium and will also reduce dandelions and other weeds in your lawn, unlike dolomtic lime. Calcitic lime is hard to find, but I bought some yesterday at Russell's Nursery in Route 20 in Wayland. If your raised beds are deep, you only need to replace the top six inches of soil every year but the vegetables will do better if you replace the whole thing.
Carol_Stocker: Dear Steve,you can also use an organic fertililzer such as Cockadoodle DOO, or a time release fertilizer such as Osmacote. Apple D'Or charges about $40 to deliver compost in the Boston area.
bh__Guest_: hi carol, i miss your column! i don't see it in the style section. i dug up part of my lawn and made a garden. but almost everything i plant there dies. when i turn over the soil i see grubs. are they eating the roots of my plants? the only things that have survived are catmint and artemesia. any suggestions for other perennials?
Carol_Stocker: I'm not writing a weekly column at this point, but I am still writing articles for the Style section. I have one in today about making the transition from a chemical to an organic lawn. I am also on WGBH TV's Greater Boston with Emil Rooney sometimes, depending on how much email they get about me from fans. I was on this Monday talking about the disappearing honeybees and the mysterious hive collapse disorder. Now aout your garden. It sounds like you had white grubs in your lawn, which are immature Japanese and chafer beetles. They are c-shaped tiny white worms with hard black heads. When you dug up the lawn, they stayed in the soil and switched from eating your grass roots to eating your perennial roots that you had planted. Right now the grubs are at maximum size and it would take a powerful poison to kill them. It is better to let them go to sleep and then emerge from the ground as beetles and fly away. At that point, they may decide they like lawns better than perennials and fly to someone's lawn to lay their eggs and leave your perennials alone. (Have you had this problem for longer than 12 months?) In August, turn over some soil in our garden, take a magnifying glass and see if you can find some tiny versions of the grubs, which would be a new generation. If you find more than five or six, apply the insecticide Merit, following label directions. The smaller grubs, if present, will be much easier to kill than their parents.
chris__Guest_: Hi Carol, I've noticed a lot of sickly looking rhododendrons around - mine included. Is there anything I can give them to revive them and get their normal leaf color back. A lot of my leaves are lime green - thanks
Carol_Stocker: They are probably lacking iron. Apply some Hollytone now, an acidic fertilizer especially for broad leaf evergreens.
andy_lions__Guest_: what should i plant on my shady slope for august/september/october bloom?
Carol_Stocker: Good question! Most shad tolerant plants bloom in april/may/june. That's because they like to flower before the trees leaf out and add to their shade. Most flowers that bloom in summer and fall are sun lovers, but there are some exceptions. Many types of hostas will bloom in those months. You need to go to a hosta expert such as Seawright Gardens in Carlisle, MA, and ask them what varieties bloom in those months. Hostas can be expensive but they are easily divided to create more plants. After three years one hosta can be dug and and divided into a dozen sets of roots. The same is true for black eyed Susan (Rudbeckia Goldsturm, which blooms in August, and Sedum Autumn Joy, which blooms in September and October. These are the three best late season bloomers for ground covers for shade. I would use all three and interplant them with impatiens for the first couple of years until they grow into a solid carpet.
Aja1__Guest_: Carol, something bit the tulips neatly off each and every stem!! What is doing this and how do I stop them?!?!
Carol_Stocker: You probably have deer, who love to do that to tulips. They eat the flowers but leave the stems. It could also be rabbits or ground hogs. In any case, it is too late to save your tulips by the sound of it. You have two options. One is to spray tulips and other things they eat with a deer repellent such as Deer Away. This does work but you have to do it every couple of weeks. The other choice is to pull out all your decapitated tulips since tulips are really expensive annuals anyway and seldom bloom more than two years, and after they bloom you have to put up with ugly ripening yellow foliage. This fall you have a choice of planting more tulips, but I would plant daffodils and ornamental alliums (onions) instead as these are two bulbs that animals don't eat.
sandraj__Guest_: I am desperate for ideas of what to plant to maintain a small incline on a marsh lands? the area does not get soaked, but I need some growth to maintain the land and survive near the salt water air.
Carol_Stocker: So this is salt water and full sun I assume? In any case, you should plant things that can survive without fertilizer or pesticides as salt water marshes are nurseries for baby fish that will eventually populate the ocean. rosa rugosa may be your beest choice, followed by pines, artemisias, salvia and perhaps some lavenders or succulents.
Carol_Stocker: Check the New Englanb Wild Flower Society (NEWFS) website for suggestions of native plants that might be suitable. they also run a nursery and if you need a large number, they will grow them for you as part of an order and they are not expensive.
mark0624__Guest_: I have a peach tree that is on its last legs (few flowers and lots of dead branches). I would like to replace it with a Kousa Dogwood. Do I need to dig up the entire tree or can I just cut it down? Please advise. Thanks!
Carol_Stocker: You can just cut it down. The roots will rot in the soil and serve as fertilizer for the kouza roots.
emily__Guest_: Now about lawn care... Our lawn is pretty shabby. I put down corn gluten last weekend and I also know I need to lime it. Is there any harm in putting down lime now, right on top of the corn gluten? or is it better to wait awhile? If so, how long? Thanks again!
Carol_Stocker: Read my article about lawn care in today's Style section. I advise against corn gluten here. There's no harm in putting down lime now, but make sure it is calcitic not the usual dolomitic lime.
dgreen__Guest_: I was thinking of using potato vine as an annual ground cover to weave in between my perennials. Will it spread like it does when planted in pots? Thanks!
Carol_Stocker: Why not?
chris__Guest_: Hi Carol, I obtained an old cold frame last year - wood frame and glass. How soon may I put vegetable seedlings out in the cold frame. they will be planted in the ground and frame placed over. Also,How should I maintain the plants once there in - in terms of opening/closing the windows on the cold frame? thank you!
Carol_Stocker: Put the plant in now and order an automatic device that opens and closes the top based on the temperature. Gardener's Supply in Burlington Vt sells one mail order.
Carol_Stocker: I'll be back on line Thursday, May 24 at 1 p.m.