Archive | September 2016

Save your Heirloom Tomato Seeds

'Mr Stripey' heirloom variety tomato

‘Mr Stripey’ heirloom variety tomato

I like to try different kinds of tomatoes each year and, while the hybrids produce really good and generally disease-free fruit, there’s nothing like biting into a tomato that reminds you of your childhood. That happened to me this summer with one that I hadn’t tried before — ‘Mr. Stripey’. Now, we didn’t grow ‘Mr. Stripey’ when I was a kid (not to my recollection anyway), but it has that full, just-from-the-garden sweetness that I remember. As a result, I thought I might try seed saving this year — something I’ve never done. For help, I’m taking the advice to Diana Alfuth, horticulture educator for Pierce & St. Croix County UW-Extension.

Seed Saving

by Diana Alfuth

Saving vegetable seeds from year to year can be fun and economical. Self-pollinating plants, such as beans, peas, tomatoes and peppers, are the best vegetables to save. Vine crops, including squash, pumpkins, melons and cucumbers, are often cross-pollinated by insects, so seeds saved from these crops will likely grow into plants that produce fruit unlike that of the parent plant — often odd shaped or poor tasting.

For tomatoes, scoop the seeds and gel from the middle and put them in a jar of water. Stir the mixture daily and after four to five days, the gel will break down and the seeds will fall to the bottom. Pour off the liquid, collect the seeds, and place them in an even layer to dry. Coffee filters work really well for this purpose since they absorb moisture and you can write the variety name directly on the filter. For peppers, remove the seeds from ripe fruit after they begin to shrivel and put them directly into a filter for drying. Beans and peas can be left on the plants until dry and rattling in the pods, and then shelled for storage.

Once fully dry, store the seeds in a cool, dry place, ideally at 32º to 41ºF. Put your seeds in individual paper envelopes, and then put them all in a glass jar in your refrigerator or other cool place until planting time next year. Be sure to mark the envelopes with the date and variety.

Summer Bulbs

Overwintering Summer Bulbs

by Diana Alfuth, horticulture educator for Pierce & St. Croix County UW-Extension


Tender summer gladiolus

Summer bulbs cannot make it through our cold Wisconsin winters. If you want to plant them again next year, tender bulbs must be dug and stored once the foliage begins to yellow or is killed by frost. Cut the foliage to about 2 inches, dig the bulbs with a spading fork and knock off most of the soil. Don’t wash canna, dahlia or caladium bulbs, but hose off others, if needed. Discard any bulbs with spots or sunken areas, which may indicate the presence of disease.

Once bulbs are dry, pack them with some peat moss, sawdust, perlite, vermiculite or sand, or put them in thick paper bags and place them in a cool, dry place for winter. A root cellar, unheated basement or extra refrigerator can be used to keep temperatures between 50 and 65ºF, or 35 to 55ºF for gladiolus. Don’t store bulbs with ripening fruit, such as apples. The fruit gives off ethylene gas, which can damage bulbs.

Check the bulbs periodically over the winter. If mold is present, spread the bulbs out to dry or otherwise reduce humidity. Separate the bulbs prior to planting next spring.

Planting Summer Bulbs

from The New York Times column ‘Garden Q&A’

Summer bulbs are tropical types that want summer conditions. They will start sprouting when the soil is still less than toasty, but if it is downright cold, they’ll sulk, and if they sulk in soil that is damp as well as cold, they’re likely to rot.

So people in short-season areas have two options: the first is simply to wait for warm weather and then wait for flowers; the other is to give plants like crocosmias, acidantheras, and dahlias a short head start indoors.

Since you don’t want to have to worry about providing greenhouse conditions, wait until it’s near the frost-free date, then plant your summer beauties in a free-draining seed-starting medium like Pro-Mix. Water well, then set the pots (or for small bulbs, plug flats) where they will be warm but not hot, 60º to 65ºF. Add water only as necessary to keep the soil barely moist, and do not fertilize.

It should take a couple of weeks before sprouts show above the soil and start needing light, by which time the weather should be warmer. Set the plots outside in a sheltered spot where they will get plenty of sun but be protected from cold winds, and be prepared to move them indoors if the temperature threatens to go below 55ºF. Once you’re sure the weather has settled in a warm direction, transplant into the garden.

Overwintering Geraniums

8387268_origSometimes you have a perfect summer with conditions that have contributed to the most beautiful container of geraniums you’ve ever had. What to do in the fall — let them die off and try again next year, or attempt to keep them over the winter? If you’re tempted to keep them, you have some options.

The perfect solution would be a cool, damp basement (can you say cellar?), where you could just hang them upside down. Shake the excess dirt from the roots, but leave all that clings. Loosely tie a string around the neck area, where the stem meets he roots, and use this to hang them from a rafter or beam. They should get good air circulation; be sure they don’t touch each other or anything else.

A dry basement — as long as it is cool (35º to 45ºF) — is a distant second choice. In that case, you will need to pot them up and they will need a place that’s light. They should be watered thoroughly about once a month, but let them go dry in between — they’re hardly growing.

No matter which way you store them, remove buds and flowers, where the disease botrytis hides, and any leaves that turn yellow. Cut the plants back to 6 inches after planting them outside next year.

Even thought your geraniums appear healthy, they could have picked up at least one of the many diseases that affect geraniums during the summer. When they are ready to go back outside, the geraniums will be stressed from their winter treatment, but any disease organisms will be just fine so the plants may not be as healthy as you expect. Keep a little extra in the gardening budget for replacements.

Allergies of Autumn


Beautiful stems of Goldenrod – mistakenly blamed for Fall allergies

Poor Goldenrod (state flower of Kentucky) — blamed for the itchy, watery eyes suffered by so many this time of year (including me!). It’s a shame that goldenrod is blamed for the sneezes and wheezes of autumn allergies, so I am, once again, writing an article in defense of this beautiful garden plant!

The reason, I’m sure, that so many people think of goldenrod as their autumn nemesis is because it produces those brilliant yellow flowers just when ragweed also blooms. But no one notices the culprit’s small homely pale green blooms. Goldenrod’s pollen is heavy and is moved about only by bees, whereas ragweed pollen is tiny and light and meant to be spread by the wind.

There are some 15 species of common ragweed, whose botanical name is Ambrosia (an ironic misnomer for sure). Ragweeds grow naturally from coast to coast, adapting to both country meadows and gritty city environments. The plant has fernlike leaves similar to those of wormwood (Artemisia), and is actually a tasty treat for pigs and cattle.

Ragweed is also an excellent soil preserver and conditioner, one of the group, sometimes called pioneer plants, that spring up rapidly after floods, fires, or bulldozers have ravaged the earth. So, a very useful plant for both the Earth, and for the pharmaceutical companies that collect lots of my dollars every fall as I struggle to breathe without crying!

Fall Blooming Asters

by Dr. Leonard Perry, Horticulture Professor, University of Vermont


Aster amellus ‘Violet Queen’

There are many reasons to use fall-blooming asters in landscapes. There is much variety in this large group of hardy perennials, coming in various heights and showy flower colors. You’ll find selections in all shades of red, pink, purple, white, and even blue. They’re easy to grow, most are native, and they’re one of the main plants for bees, butterflies and other pollinators in the fall. They combine well with ornamental grasses, rudbeckia, and coneflowers. With so many to choose from, how does one begin? In addition to favorite colors, look for ones that best fit your growing conditions, desired habits, and disease resistance.

The starburst appearance of the flowers leads to the name “aster”, from the Greek word for star. Asters give their name to the large composite family—Asteraceae—that of sunflowers, dahlias, daisies, zinnias, and similar flowers. The asters all used to be grouped together into one “genus” (Aster), but thanks to recent botanical research they’ve been regrouped with names more suited to botanists than gardeners. So for instance, although the New England aster genus is now changed (Symphyotrichum), the species name has remained the same (novae-angliae).

Generally, most asters prefer moist, well-drained soil and full sun. There is a range of species, however, that can be grouped by their native environments and corresponding garden preferences. The first group prefers rich, moist soil in full sun. These include the species native to meadows, prairies and marshes such as the New York (S. novi-belgii), New England (S. novae-angliae), and flat-topped (D. umbellata) asters. They prefer steady moisture. Ones that prefer moist soil, but can tolerate dry sites, include the sky- blue (S. oolentangiense), heath (S. ericoides), calico (S. lateriflorum), aromatic (S. oblongifolium), and silky (S. sericeum) asters. Tatarian aster (A. tataricus) in this group, a Siberian native, is quite adaptable to various soils.

The second group of asters also prefer full sun, along with cool nights, and very well-drained soil. This is because they are native to seashores and mountains where soil drainage is excellent. They may be short-lived over only a few years,particularly if conditions aren’t just right. In this group you’ll find the European Michaelmas daisy native to Asia Minor (A. amellus)—a name often given to many asters as they bloom around this Christian  holiday of September 29. Others in this group are the Frikart’s (A. xfrikartii) aster, of garden origin, and East Indies (A. tongolensis) aster native to western China and India.

The third group of native aster species tolerate shade (under 4 hours direct sun per day), but bloom better in part shade (4-8 hours of direct sun). The blue wood aster (S. cordifolium), Drummond’s aster (S. drummondii), white wood aster (E. divaricata), and big leaf aster (A. macrophyllus) are in this group. Although they prefer moist soils rich in organic matter, they will tolerate some drought.

In perennial trials at the Chicago Botanic Gardens (www. planteval_notes/no36_asters. pdf), 119 asters were evaluated over six years. They were rated based on flowering, health, habit, and hardiness. In this USDA zone 5 site (-10 to -20F average winter minimum), seven asters stood out with five-star ratings. These top asters included ‘Jin Dai’ tatarian aster, white wood aster and its cultivar (cultivated variety) ‘Eastern Star’, ‘Snow Flurry’ heath aster, calico aster and its cultivar ‘Lady in Black’, and ‘Raydon’s Favorite’ aromatic aster. For a rock garden or low wall, where cascading stems are desired, ‘Snow Flurry’ would be a good choice. For perennial gardens and naturalistic landscape masses, good choices would include asters with bushy habits—‘Jin Dai’, ‘Lady in Black’, or ‘Raydon’s Favorite’.

In addition, there were 19 asters that rated good, with four stars. These good asters included a couple of New England asters— the rosy pink ‘Harrington’s Pink’

and deep pink ‘Honeysong Pink’, and three New York asters—the light lavender ‘Blaubox’, lavender- blue ‘Climax’, and purple-pink ‘Rosenwichtel’. Most selections you may find of the asters are in the New York and New England species. Perhaps the reasons that more didn’t rate more highly relate to habit and potential problems. Aromatic asters tend to be less problem-prone, and good alternative choices.

New England asters can get to four to five feet tall and fall over under some conditions, particularly low light. Cutting them back in early summer by one third to one half will make them more bushy, with no need to stake.


Aster ‘Purple Dome’

One of the more recent introductions of New England asters, and one of the most popular asters, ‘Purple Dome’ came from the Mt. Cuba Center and gardens in Delaware. It is violet-purple and low, only growing to about 16 inches high and about 2 feet wide. This makes it a good choice for fronts of borders, along walks, massed, or even containers. It bloomed over two months in Chicago, from early September to early November. ‘Vibrant Dome’ is a bright pink sport of this compact cultivar, not in these trials but popular and available.

‘Purple Dome’ is a good example of how resistance to diseases can vary by site. Often considered to have excellent resistance to powdery mildew, in the Chicago trials this cultivar was only rated as fair.

Asters may get rust or powdery mildew diseases on leaves. The former was seen more on the New York asters in the Chicago trials, while the latter disease was seen more on the New England asters. Giving good air circulation around plants, and disposing of leaves in the fall (not in the compost bin) will help lessen these. There are several sprays, organic and synthetic, that can be used for these too. A main destructive insect of asters may be the lacebug, a small grayish insect that appears in midsummer and sucks the plant juices from the undersides of leaves, primarily of the New York and related types. Leaves turn yellowish and eventually brown and fall off. Organic or synthetic insect sprays can be used for control. Read and follow all label directions for best control, and safety for you and the environment.

Deer and rabbits can be quite fond of asters, too. There are repellent sprays for these. Low fencing for rabbits, and deer netting for these may be needed if repellents don’t work. Several asters have been bred as alternatives to fall garden mums, including the lavender ‘Ariel’, violet ‘Celeste’, and the purple ‘Pixie Dark’. Results from the Chicago trials show these only live a year or two, so should be grown as annual flowers. Since the New York asters have problems, and are short-lived, they are not recommended either, even though commonly found.

Keeping asters healthy during the growing season—in part, growing them under the right conditions—will go a long way toward helping them survive the subsequent winter.


Fire in the Fields

Sumac lighting up a hill in Wisconsin's autumn

Sumac lighting up a hill in Wisconsin’s autumn

It happens every autumn. Huge sweeps of straggly, undistinguished shrubs that grew unnoticed in unkempt fields are suddenly, gloriously, ornamental. The long almost palmlike fronds of leaves shine bright red with hints of yellow and orange. The branches spread like candelabra holding up huge crimson fruit clusters that keep glowing long after leafdrop, when all the world is gray. No wonder gardeners think about bringing sumac in from the wild.

Staghorn sumac in the summer before changing color

Staghorn sumac in the summer before changing color

Sumac grows everywhere, all the way from zone 2 to zone 9. It grows in dry soil, poor soil, moist soil, near-bog, bright sun, and part shade. It spreads by seed and by underground runners that can travel 20 feet or more in search of a good spot to make a new clump of sumac. But if there is also a lawn anywhere nearby, there will be adequate local control as long as you keep mowing.

Smooth sumac (Rhus glabra) is the most common roadside attraction. It’s fuller and more readily clump-forming than staghorn sumac (R. typhina), named for the velvety down that covers every branch. Smooth sumac tops out at about 8 to 10 feet, staghorn at 12 to 16 feet.

Fragrant sumac makes a beautiful garden addition

Fragrant sumac makes a beautiful garden addition

Fragrant sumac (R. aromatica) is shorter, at 3 to 4 feet, and bushier, more like a garden plant. If you decide to bring sumac into your garden or prairie, no matter which type you choose you will need both male and female plants if you want fruits. Sumacs are available through nurseries that specialize in native plants, and some large garden centers will order them for you if you ask.

Note: it’s always a good idea to check whether a plant is considered an invasive species in your state before transplanting from an area where the plant is growing wild. In Wisconsin, the Department of Natural Resources provides a free guide to invasive species here:  DNR INVASIVE SPECIES GUIDE


When to Plant Trees

tree-planting-guide-diagramFor most trees, fall is the best time to plant. The soil is warm but not waterlogged the way it can be in spring, and trees without leaves make fewer demands on their roots to provide nutrients.

A few trees, however, including magnolia, birch, hawthorn, black gum, tulip tree, and most oaks, get downright cranky when planted in the fall. No one knows for sure, but researchers think that there is something that prevents the root structure from taking up enough water to overcome transplant shock, and that winter comes before the tree is ready for it.

Studies by Dr. Nina Bassuk at the Cornell University Urban Horticulture Institute in Ithaca, New York, show that transplanting these trees when they are smaller increases the success rate for fall planting. She has had much better results with trees that measure less than 2 inches in diameter at a point 6 inches above where the trunk emerges from the roots than she has had with larger trees. Be sure to water that new tree in well. Whether it has leaves or not, it needs water.

Watering also settles the soil and helps eliminate any air pockets. Dormant trees planted in October or early November should need only that one deep, soothing watering to last them the winter. But all that said, it is still better to plant magnolias in spring.

Like other things in life that aren’t what they used to be, burlap has changed. Whether for the better depends on your point of view. A single layer of plain old untreated burlap, now almost a thing of the past, rots away nicely and lets roots wander freely out of their soil ball. But you are just as likely to run into a plastic burlap-like material, or into burlap that has been treated with a rot-resistant chemical.

Both are popular in the horticultural industry for the same reason: they stay intact longer, through sunshine and waterings, as the tree makes its way from its growing site to you. But that perseverance presents problems for growing roots trying to find their way into new surroundings. Rot-resistant burlap takes years longer to decay than untreated does, and even untreated burlap presents a formidable boundary if wadded down in layers and left in place.

In both cases, these barriers restrict the diameter of the roots as they grow out. In some cases, the tree may even die. At that point, you can dig it up and use the original wrapping to take the dead tree to the dump.

To avoid such problems, after placing the tree in that nice extra-wide-but-no-deeper-than-the-ball hole, untie the twine around the trunk and cut away the burlap.

Note: some ideas are harder to kill than crabgrass. One of them is that when a tree is dug up to be sold, the branches should be removed to compensate for the loss of roots. The rationale is to balance root loss with the removal of an equal amount of top growth. The tree is then thought to be better balanced and better able to withstand transplant shock.

As logical as this sounds at first, it just doesn’t hold up. The human equivalent might be removing the right arm of someone who has just lost her left leg in an accident.

Transplanted trees need all the food they can produce to support the regrowth of those lost roots. The food comes from leaves doing their thing, so the more leaves, the better. The only branches that should be pruned are those that are dead, diseased, damaged, or rubbing against other branches.