Drying Hydrangeas

In July, when the Hydrangeas are at their most blue, blue, many people pick the flowers and attempt to dry them. At this point the blossoms shrivel up into nothing, causing great disappointment. The flowers won't dry when they are fresh...you have to wait until later in the summer.

Once the flowers have begun to turn the mix of gray/purple or even green, and the petals are a bit more papery, they can be cut for drying. This usually happens in late August and early September. At that point, cut the flowers with a stem that's about 8" to 12" long, and strip off all of the leaves.

If you want to be sure that the flower dries in a perfect dome shape, hang the flowers upside down in a dark, dry room such as an attic. Don't let the flowers touch each other or anything else. If you're less particular about how they dry, just place the cut stems into a vase without water.

Most dried hydrangeas keep their color for three to six months when they are kept away from sunlight. If you want to use the dried flowers in holiday arrangements, cut them now and keep them in a dark place to preserve the colors until you're ready to decorate.

Hydrangea Hints

Cape Cod's favorite shrub has been in glorious bloom this year because the winter temperatures last season didn't go below 12 degrees. Because of the relatively mild winter, most of the buds made it through the cold and went on to bloom this summer. Lucky us!

This is a photo of a Nikko Blue that has been cut back in the fall or spring, probably to "neaten things up." Notice that it has grown just as tall as it was last year, and that it doesn't have many flowers. If you want your Nikko Blue hydrangeas to be flower-filled, don't cut them back. Remember that even if you prune them, they'll replace their growth in just one year. There is no making a Nikko Blue shorter.

Here are some suggestions for success with Hydrangeas:

Blooming & Not Blooming

Hydrangeas may not bloom for the following reasons:

1. Too much shade: plant them where they get at least 3 hours of direct sun for the best flowering.

2. Pruning: If you cut down the canes of most mopheads and lacecaps (H. macrophylla & H. serrata) you’ll have fewer or no flowers the following summer no matter when you do it. See pruning below.

3. Winter temperatures that go down to zero or below: this zaps the buds, killing the flowers for the next summer.

4. Warm March temps followed by a cold April: If the buds begin to swell early in the spring, and then get hit by cold, April off-ocean winds, that can be cold enough to kill the germ of the flower.

5. Too much nitrogen: Since nitrogen encourages leaf growth, too much can cause the plants to just make foliage. The most common source of too much nitrogen is lawn fertilizer.

Pruning

Prune pink and blue types in early May by removing deadwood only. Since hydrangeas will replace their growth in one summer, give up on keeping them short. Prune H. aborescens and H. paniculata (usually white) in the spring by first removing deadwood, then shaping as desired. Prune climbing hydrangeas right after flowering. Click here to read and download a pdf of C.L. Fornari's How To Prune Hydrangea Handout.

Using Hydrangeas in Your Landscape ~ Some tips for success:

1. Group hydrangeas together, or with other plants that appreciate more water. Don’t place hydrangeas next to plants that like it dry, such as sedum or junipers.

2. There are many shorter growing varieties for foundation plantings that won’t grow above the windows. Look for Endless Summer, Penny Mac, and plants in the Forever & Ever and CityLine series.  

3. Nikko Blue, the Cape’s favorite blue hydrangea, grows 5 or more feet high and six or more wide. Plant accordingly. Once they are old enough to be tall, there is no way to make them short again.

This is the original Forever & Ever hydrangea.

Mums and Fall Magic

Chrysanthemums are the fall flower... once the nights are cool, it's time to plant mums in the garden. Some of our customers wonder why their mums don't make it through the winter, however, so here's a tip to help keep your mums hardy: keep watering them after they finish blooming, and don't cut the foliage down before next spring.

Most people forget that mums have a small root system and dry up quickly. Once the flowers have faded and we've turned off the hoses in the garden, it's easy to forget that the roots of recently planted mums will dry within five days. Mark it on your calendar to water these plants every five days, and those chrysanthemums will be growing roots right into November. Once the ground starts to freeze, or in mid-December, you can stop watering.

Another trick to keeping mums alive through the winter is to leave the stems in place even after the foliage has dried. Cut these stems back to the ground in March, and watch for the new foliage in April.

In addition to mums, be sure to include some of the other plants that are available. There are many beautiful Heucheras in Proven Winners' Fall Magic collection, for example, and they are magic indeed! Celebrate the season with some new, colorful plants for your garden!

Nepeta 'Six Hills Giant'

If you want a low-maintenance perennial that is absolutely spectacular in June, plant some Nepeta 'Six Hills Giant' in your garden. This catmint grows best in full sun, and gets about two feet tall and three feet wide. 'Six Hills Giant' blooms most heavily in June and early July, but if you shear it in half after that flush of flowers winds down the plant will produce many smaller flowers for the rest of the summer. Alternatively, you can cut the plant to the ground in mid-July and it will produce a low mound of fresh, attractive foliage that will attractive well into the fall.

Like most perennials, this Nepeta looks best when planted in groups of three or more. Combine it with the later-flowering Russian sage and grasses to create gardens beautiful lavender blue flowers and wind-blown textures all summer.

Damp Weather Woes!

Anyone who lives on Cape Cod will tell you: it seems as if it's been cloudy and damp forever. Our plants are longing for the sun, and many of them are prone to all sorts of fungal or rust problems in this weather. Blackspot on roses, mildew on squash and rust on the hollyhocks are all likely to show up soon. Yikes! 

Two products offer protection or treatment for these problems: Serenade and GreenCure. Both are approved for organic gardening, so they may be safely used on edible plants as well as your ornamentals. Serenade contains Bacillus subtilis,  a natural microorginism that has been used for years to suppress fungi and rusts. GreenCure is made of potassium bicarbonate with a spreader-sticker added to hold the product on the plants. The potassium bicarbonate kills existing mildew and helps to prevent new outbreaks.

This gardener has used Serenade to keep the rust on her hollyhocks at bay: if you've had a problem with hollyhock rust, start to spray early next year and be sure to coat the stems and underneath the leaves. 

These products, like all fungicides, should be applied according to directions and are most effective when used before the plants have a problem. So this year use them as soon as possible, but next year begin to spray as soon as the plants break dormancy.