I start ‘Dragon Wing’ begonia from seed under grow lights. What other begonias can I use to cross-pollinate with the ‘Dragon Wing’ so I can collect my own seeds?
‘Dragon Wing’ is a unique hybrid type of begonia named to reflect the shape of its leaves. It is created by interspecific crosses of two different begonia species and can lead to interesting new plants, but they are sterile.
It is impossible to say exactly which species will cross and which will not cross. You can try crossing angel wing begonia, a common houseplant, with another species. There is a good chance viable seed will be produced, according to Brian E. Corr, new crops development manager at Ball Horticultural Company, West Chicago.
The American Begonia Society (begonias.org) is a resource for information on hybridizing. The archives of the bi-monthly journal The Begonian would also be helpful.
What are your three favorite “all-but-forgotten” perennials that every garden should include? Why do you like them?
Anemone tomentosa ‘Robustissima’ is a late season plant for sun to part shade and a wide range of soils. Deer and rabbit resistant with few pests or diseases. The fuzzy texture and gray-green leaves of Stachys byzantina ‘Helene von Stein’ complement other sun plants wonderfully. Leaves mask brown lower foliage of asters. The 3 to 5-foot tall Baptista australis and PRAIRIEBLUES cultivars offer gorgeous blue and purple flowers and they attract butterflies. They like full to part shade and tolerate poor soils.
My three favorite forgotten perennials are plumbago, bergenia and Stokes’ aster. Plumbago (Ceratostigma plumbaginoides) is a ground cover with sky blue flowers in fall and red leaves. Intersperse it with spring bulbs for three seasons of interest. Bergenia (Bergenia cordifolia) is versatile, handling conditions from moist sunny areas to dry shade. It is rabbit and deer resistant. When you rub your two fingers on either side of the leaf you can make it squeak (hence another common name: pig squeak). The long-blooming and easy-care Stokes’ aster (Stokesia laevis) is fairly pest and disease free. Rabbits tend not to eat it, and it attracts butterflies.
Three favorites of ours are pasque flower (Pulsatilla vulgaris), Laddie peony (Paeonia peregrina) and balloon flower (Platycodon grandiflorus). Pasque flower blooms very early in spring with extremely soft leaves and silvery green buds. Red, white or purple flowers; purple seems to have more vigor. The ferny-leaved Laddie peony also blooms very early with red flowers. It’s a hybrid of Paeonia peregrina and P. tenuifolia. Balloon flower is named for blue, pink or white flowers that start out looking like a balloon and open to look like a star. They have a long blooming period in summer.
I have some peonies that I want to transplant but cannot plant them in their permanent place until next spring when our new house will be built. Can I dig them now and transplant them again next spring?
The correct time for transplanting herbaceous peonies is late September into October. Cut back the foliage when you dig them up. Each clump you move should have at least three eyes, or growth buds, and thick tuberous roots. Dig a hole deep enough to cover the eyes with two inches of soil when you transplant. If planted too deeply, they will not bloom.
Transplant the peony into its temporary place, or else move it into a container and dig the container into a shady area, not in full sun. Be careful about watering the container plant; try to keep it evenly moist. Next spring, move the peony into its permanent location, suggests David Leider, perennial grower at Klehm Plants, Barrington.
“Replanting in spring disrupts the roots and will halt blooming for one year. Peonies are pretty strong plants and very hardy. They will recover,” says Charlotte Thayer, assistant to the owner at The Natural Garden, St. Charles.
I have houseplants outside that I will need to bring indoors. What is the lowest temperature at which I can leave them outside?
The rule of thumb is when night temperatures are in the 50s, it is time to bring your houseplants indoors, according to horticulturists at Pesche’s garden center, Des Plaines.
To avoid the shock of suddenly bringing plants into a hot dry environment, place them in a shaded area before the heat comes on in the house. Bring in sensitive tropicals such as hibiscus and anthuriums as soon as summer cools down.
Christmas cactus and cymbidium orchids can tolerate chillier temperatures and stay outdoors longer, but move them indoors before the thermometer drops to freezing, says Greg Stack, University of Illinois Extension Educator, Horticulture. Indoors, a cool 50-degree area such as an unheated sun porch will give them the short day situation they need to set flower buds. Stack keeps his Christmas cactus in a cool unused room where the lights aren’t turned on. His plant sets buds and blooms reliably every year, he reports. Christmas cactus buds will dry up in an overheated, dry room.
I want to raise the level of my lawn as much as 2 feet in places. I now have a large quantity of somewhat composted wood chips and I am wondering if I can use them as fill to raise the ground level and provide a good soil in which to sow a lawn.
“It is not a good idea to use only wood chips to raise the grade of an area,” says Greg Stack, University of Illinois extension educator, horticulture. While wood chips may raise the grade for a while, over time they will decompose and eventually the site will sink. Even using them as fill and putting soil over them is not a good idea.
“I would not use straight compost by itself to raise the lawn level, but mix it with soil,” adds Stack.
I have lost four 12-15 foot tall white pine trees over the last year. All had the same symptoms, browning needles at the bottom that continued up to the top. Can you tell me what pest is killing the white pines? I am also losing an Austrian pine now. It is experiencing the same symptoms.
White pines in this area are very rarely troubled by disease. They are, unfortunately, highly susceptible to high pH problems, or soil alkalinity, and are utterly intolerant of salt, according to Rich Eyre of Foxwillow Pines, Woodstock. The browning needles could also indicate the plant is getting too much water or has poor drainage.If environmental problems are not the issue for your white pines, consult an expert. Betty Lockwood, Plant Information Specialist at the Chicago Botanic Garden, suggested you bring them a sample branch to check on disease and bring in an arborist for an on site visit to check your growing conditions. Or take a 12-inch sample of an affected tree to your local extension office.Austrian pine is very tolerant of environmental conditions but is prone to certain diseases—diplodia tip blight and dothistroma needle blight, both caused by a fungus. Only an arborist or a laboratory can provide an accurate diagnosis. If you bring in a 12-inch sample for diagnosis, be sure to sterilize your pruning shears with denatured alcohol after cutting the diseased wood.
What is the largest tree that one can plant? We are trying to replace some 7- to 8-foot trees that were recently destroyed.
Trees sold at garden centers that are 2.5 to 3 feet tall, with a 2.5 inch diameter trunk, can be planted by hand. A hole for a ‘balled and burlap’ tree with a 5 to 6-inch diameter trunk can be dug by hand without a tree spade.
Any tree with a trunk larger than 6 inches in diameter would need a tree spade to do the moving and digging. Even large trees, such as a 35-foot tall tree with a trunk 9 or 10 inches in diameter can be transplanted with proper equipment. “Spruces 30 feet tall can be installed easily with a tree spade,” according to Greg Oltman, owner, Gro Horticultural Enterprises, Huntley.
Can you tell me if the African daisy Osteospermum ‘Springstar Aurora’ can be winterized here? It is a healthy plant?
Those South African daisies could never endure a frigid winter here and should be considered annuals. Their daisy-like flowers with blue centers open only in sunlight and bloom best in early summer or later when summer days cool down. They can be seed-grown under lights.
I would like to start seeds under lights. When is the best time to start flower seeds? The seed packet always says to sow a number of weeks before the last frost. When is the last frost?
“In this area we use May 15 as a benchmark for the last frost date, but it can be earlier or later,” says Chuck Prosek, grower at Prosek’s Greenhouse, Winfield.
If your seed packet gives you the number of days to germination, add that to the number of weeks for growth, and then count the number of weeks back from May 15. Tomatoes sown indoors generally need 6-8 weeks of growth before being set out.
Many seed packets do not include germination time. A good guess is to allow 1-2 weeks for the seeds to germinate, but if you use bottom heat, your seeds will germinate earlier and grow faster. Most seeds need warm soil of 65 to 70 degrees to germinate and grow.
When you sow seeds directly into the soil, till the upper inch of soil to loosen it for direct seed to soil contact. The outside soil temperature must be above 50 degrees for cool growing plants, and at least 65 degrees for warm season annuals, according to Prosek.
For future reference, keep a record of indoor sowing dates, germination dates, length of indoor growing period, and transplanting dates.
Must I mulch my garden and, if so, when is the best time to apply it? What are the best materials to use?
Perennial gardens usually come through the winter better when given some sort of protection, although many gardeners leave their established gardens unprotected save for deer netting to keep deer off newly emerging greens in spring. Plants new to your garden can be protected by mulch during the first winter and may not need it after that.
Mulch is used in winter not to keep the plants warm, but to keep the ground at an even temperature and prevent plants from heaving out of the soil during periods of alternate freezing and thawing. Thus it is applied after the ground freezes. If mulch is applied before the ground freezes, it can smother the plants.
The simplest mulch is a loose layer of oak leaves, which do not mat down and rot. Ground-up leaves are ideal, and even dried grass can be used. Or apply straw left over from Halloween decorating.
Use only a few inches of mulch and keep it light enough not to smother the plants. Deer netting helps to hold mulch in place until it is wet enough not to blow around. In spring, as soon as the plant starts to grow, remove the mulch gradually, a little at a time over several days. Don’t wait too long because if the shoots are too tall, you may damage them as you pull off the mulch. Work the mulch into the soil with a trowel afterwards.
Heucheras, astrantias and recently planted perennials may heave even if mulched. Push any dislodged plants back into the soil. Mulch also protects the evergreen rosettes of biennial hollyhock, foxglove, Canterbury bells and sweet William from snow and ice damage.
My lilac had a grayish blight on the leaves this summer. What caused this and how can I prevent it?
From what I have read, hellebores are supposed to spread. I have a few I planted four years ago, and they seem to be the same as when I planted them. They are planted in a bed of vinca. Should I remove more vinca that surrounds them? I do fertilize them and protect them with a winter mulch. What else should I be doing to have more plants?
I have a nicely sheltered, rounded 7-foot tall Japanese red maple on the southeast corner of my backyard. Half of the tree has lost its leaves, the formerly red bark is turning gray, and a good-sized square of bark has been stripped off on the side that faces the yard. I sprayed the exposed bark with black pruning spray to close any entry for insects. I have not cut off any of the branches.
Does the winter have any effect on the tree? Should I look for some insect infestation? What should I do now?