The newest hardy and robust flowers

This week, we continue our tour of what’s new for the garden in 2010 when it comes to flowers.

First, a few words about hardy chrysanthemums. Because if you want to grow your own, and grow some of the new varieties, you need to order these plants now so you can plant them in the spring.

Contrary to what you might think, if you wait until the fall when the potted plants are at the garden centers, you are definitely buying mums but you are not necessarily buying hardy mums. In many cases, they have been chemically treated to keep them short and compact.

The good news is that you can grow your own without chemicals at a fraction of the cost. The trick here is to order your mum starter plants now. They are delivered in the spring in small pots and will range in price from $3 and up.

Plant the starters in the locations where you want them blooming in the fall and simply keep them “pinched” or debudded through early July. Feed them and keep them free of insects, then come late summer and fall your investment pays off with full-sized blooming plants.

If you don’t want the mums planted in your beds right away, they can go into a nursery area. Hardy mums are easily transplanted late in the season as they are shallow-rooted and can be moved on a cloudy day.

Growing mums this way gives you access to a much wider variety of plants than you can buy at garden centers—not just in terms of colors, flower types and sizes, but also in height and spread. If you’re not familiar with mums and how diverse a group of plants they are, then you’re in for a surprise.

In addition, mums that you’ve grown and you know are hardy can easily be divided in the spring and you can usually get four divisions from each year-old plant. That’s a pretty good dividend return.

Another good aspect about growing your own is that after the first year, you’ll know exactly when they bloom and how they best fit in your garden. Keep in mind, though, that if you move them and the amount of daylight they get changes, the

date when they flower may also change. In some cases this might just be by days, but with more shade, flowering can be delayed by weeks.

Hardy mums as small plants are rarely, if ever, available at retail stores but a number of mail-order nurseries offer a small selection. Several offer extensive selections or exclusive varieties, including Bluestone Perennials, Spring Hill Nursery and Niche Gardens, to name a few.

Bluestone Perennials (bluestoneperennials.com) offers more than 40 varieties and collections, including buttons, cushions, daisies, football, spoon and quills, as well as standard garden mums. All are sold in packs of three for about $4 a plant.

Spring Hill Nursery (springhillnursery.com) is offering hardy mammoth mums that were developed by the University of Minnesota. These are going for about $8 apiece.

Niche Gardens (nichegardens.com) offers one of my all-time favorites, the Apricot Korean, at $10 each. I’ve found this to be one of the hardiest, easiest and latest bloomers.

For those of you who are as hooked on delphiniums as I am (you should be), Thompson & Morgan (tmseeds.com) is offering several new varieties in their “Centurion” line this year and all are F1 hybrids.

T&M claims that the Centurian Lilac Blue Bicolor is one of the highest quality delphiniums that can be grown from seed and that it rivals cutting-raised plants. Growing up to 5 feet tall, the flowers are duplex (triple-layered petals) in a combination of lilac and fluorescent blue shades with a distinct white bee. Sown in late February, blooming can last from July through September and then again the following year May through July.

T&M is also offering a new digitalis (yes, another of my faves) called “Pam’s Split.” This is not a perennial variety but a hardy biennial that is sown one year and it flowers the second year. It grows to 4 feet, and unlike most digitalis, it sports multiple stems from the basal crown of foliage. The flowers are composed of white blossoms with a speckled throat and split lower lip.

Seed should be sown in June or July to get flowering the following spring into early summer. It may self-seed and come back or you can save seed and resow. But remember, since it’s a biennial, if you do only one sowing it will show up in your garden only every other year. However, if you sow the seed two years in succession, the alternate sowing will allow for flowering plants to mature every year.

We’ve all seen a plethora of echinacea offerings in recent years. I’ve tried many of them and I’ve found the colors of some of them to be just spectacular, but the plants they grow on have not all seemed robust and durable. This year there’s a new one called “PowWow Wild Berry” that is said to differ in its flower color, branching and plant size, which could be a very welcome change.

The flowers are a deep rose-purple that measure 3 to 4 inches in diameter. And unlike other cone flowers whose color fades at maturity, this one holds its color much longer. It reaches a height of up to 2 feet and blooms continuously without deadheading. PowWow will be most prolific when our daylight is 14 hours long.

The variety will be available both as seed and plants. You can seed directly in the garden or nursery for flowering next year (it is a very hardy perennial), or you can start seed indoors next January for flowering that June. It’s critical not to cover the seed, though, as this is a light germinator.

There is also a new gaillardia this year called “Mesa Yellow.” This is the first F1 gaillardia, and unlike earlier varieties, this one has a controlled—as opposed to floppy—habit and is a prolific bloomer with globe-shaped seed heads that add to the growing season appeal.

Used in the garden or for cut flowers, the plant matures at about 18 inches and grows in full sun. Since the plant’s habit is more controlled than other gaillardias, its neat mounds fit better into garden settings and containers where the blooms can cascade down.

The new viola, “Endurio Sky Blue Martien,” has performed very well in trials all over the country and can be used in both the spring and fall garden. This species is not fond of the summer heat and humidity out here, but it is cold-tolerant and can be used in beds and planters very early in the season and will hold its own until the heat of June. It can then be replanted in late summer and it will continue to provide color right into November if you can keep the deer and rabbits away from it.

Well-suited to planters, window boxes and the landscape, the ¾-inch flowers are a clear, sky blue with the traditional darker pansy markings at the center of the flower and small yellow throat. The plants tend to be spreading and mounding, growing 6 inches tall and up to a foot wide.

I don’t often write about marigolds but in recent years I’ve seen some incredible marigold gardens and displays. So that may change.

Another good point about some types of marigold is that it they have wonderful insect repellency and can be used in the flower and vegetable garden as a companion planting. The ones that seem to offer this effect are the African marigolds (a misnomer as they are native to Mexico).

This year there’s a new one available called “Moonsong Deep Orange.” The flowers are more than 3 inches wide on plants that can be from 12 to 15 inches tall. The seed (large, and therefore great for kids to work with) can be easily started indoors now for planting outdoors when the night temperatures stay in the 50s. Sowings in-situ can take place when the soil temperature outdoors is about 70 degrees, for flowering later in the season.

The plants are strong and vigorous and the flowers are fully double and more golden than orange. They do not need to be deadheaded but will do best in full sun. If used in the garden, take care not to let taller plants or vegetables shade them too much. Also, take care not to overfeed them as this will result in lush green plants with few flowers.

Back to last week’s topic—vegetables—for a few moments in closing. For the veggie garden, growing bags or plastic bags that contain a growing medium (where plants or seed is grown right in the bag) have been popular in England and Europe for years. However, the idea never really took off here.

But if you’re short on space and want to try your hand at growing potatoes, White Flower Farm (whiteflowerfarm.com) is offering a simple system to grow potatoes in 18-inch-wide by 15-inch-deep growing bags on the balcony, porch or wherever. Two bags and the tubers cost $36 and the bags are reusable. Spuds for all.

Keep growing.

Andrew Messinger has been a professional horticulturist for more than 30 years. He divides his time between homes and gardens in Southampton, Westchester and the Catskills. E-mail him at: Andrew@hamptongardener.com. The Hampton Gardener is a registered trademark.