Pruning Hydrangeas

People really get confused about how to prune hydrangeas, probably because they look dead in winter and then bloom poorly in the summer.

DON'T PRUNE TO FIT
Trying to make it a smaller plant to fit the space won't work. Instead look for a plant to fit your space. There are many varieties that will stay smaller in comparison to their full sized counterparts. Some of our favorites are 'Mini Penny', 'Little Lime', 'Pia', and if you are looking for an oakleaf hydrangea check out 'Pee Wee'. Just remember pruning is not the same thing as deadheading (removing old blooms).

OLD WOOD vs. NEW WOOD
It is important to know whether your hydrangeas bloom on old wood (existing stems) or new wood (new spring growth).

OLD WOOD
For a visual aid on pruning Mop Head and Lace Cap hydrangeas, click here. This is a resource provided by the website, gardenlady.com. You will find a good line drawing with straightforward information. Remember that pruning after July will most likel take off some flower buds. Another reason not to prune late is the potential for a delay in dormancy; new growth forced could be hit by frost and really make the plant ugly or even possibly kill it.

NEW WOOD
This is the most straightforward group. It includes H. arborescens ("Annabelle") and other favorite varieties such as "Limelight," "Little Lamb," and more. They may be cut back if needed immediately after flowering and may rebloom if there's enough summer left and the plant has adequate food (Hollytone). When "Annabelle" blooms, cut 12" of stem to best display the beauty in a vase and it will rebloom to your delight without the flop due to the stronger stems. The second bloom will be slightly smaller flowers but still very worth doing.

• Method 1: cut ALL stems at ground level. This will produce a large number of flowers but they may flop over because the stems aren't as sturdy and the flower heads are heavy.

• Method 2: Cut the stems to a height of 18" to 24" above ground level to provide a sturdy framework to support the new growth. This framework will help control the tendency to flop.

A tidbit of trivia on the "Annabelle" hydrangea: Many thanks to the two belles, Harriet and Amy Kirkpatrick from the community of Anna in Union County. Harriet spotted it while horseback riding back in 1910. With her sister Amy, they returned the next day and dug it up. Bam! We have "Annabelle" thanks to those two belles.

This season we also have the "Invinciball" hydrangea which has a much larger white flower when compared to "Annabelle." We should also see the brand new "Bella Rose" Hydrangea; a strong pink "Annabelle" with strong stems.

EVERBLOOMING HYDRANGEAS
This is a growing list of repeat flowering shrubs both mop heads and lace caps. Their growth habit is to bloom, rest, and then repeat another bloom in the same season. Some of the named varieties are "Penny Mac," "Mini Penny," Twist N Shout," and "Blushing Bride." They all enjoy morning sun, moist, organic soil that will have soil moist reserve capacity. The soil needs to feel almost like a damp sponge. The really nice thing about this group is that no matter how you whack them they can still bloom. The color of the flower on some of these will depend on your soil pH.  Please remember that if your plant already has flower buds on it you will not be able to change the color at that time. You get what you get!

SOIL pH
The very best way is to test soil at the Ellington Agriculture Center (615) 832-5850. They need about two handfuls in a baggie. Take the sample from about 12-15” deep, where the roots would be found. Ask for the basic soil test for the acid loving trees and shrubs recommendations, to get the best blue color in the flower. They will tell you how much sulfur to use per 10 sq. ft. to get a pH number of 5.5-5.7. The way this dab of chemistry works is that the acidic soil dissolves aluminum, and it’s this aluminum that will make the flower blue. We are not fans of aluminum sulphate! At high levels it’s toxic to the plant! And with a heavy handful you can get the cremation effect. For pink, it’s so simple, our soil is derived from limestone rock and at best it will be weakly acid to neutral. Aluminum does not dissolve, thus the flower will be pink.

ADDITIONAL TIP ON HYDRANGEAS
Once in a while you will encounter a reason to skip a season of bloom. One of our horticulturists notes the following, "I did this when I first planted a very young ‘Limelight’. First I pruned it to develop its structure. Next, I used Hollytone fertilizer as a little extra food. This brand is all organic, and non-burning and contains very low soluble salts. Under normal conditions, it last 60 to 90 days. Next, I did NOT allow flower buds to develop. In effect, this will direct energy to the root system. Remember that flowering is an energy draining process by the plant. This will help redistribute energy to other neglected areas to help overcome stress from drought or insect damage."

Spring Pruning

Okay, Nashville’s winter has been pretty darn good. These bright sunny days are a great time to get out and do the things that need to be done. We get questions about pruning every single day at our garden center, and we want to give you some directions before you get outside with your hedge trimmers.

TWO THOUGHTS ON PRUNING:
• Know why the plant is being pruned and what your goal is before you start
• Time your pruning properly. The wrong timing will result in no flowers or fruit.

SOME REASONS FOR PRUNING:
• Train the plant to a desired form or special garden form (i.e. topiary)
• Control the plant size
• Protect people and property
• Maintain plant health
• Remove dead or dying branches
• Remove branches that rub or are starting to grow through the center mass of the plant
• Remove unwanted suckers and water sprouts
• Remove branches injured by disease or severe insect infestation
• Rejuvenate and restore old plants
• Ensure the quality of flower, foliage, and stems
• Encourage flower and fruit development
• Maintain the density of a hedge
• Delay the bloom time for landscape plantings
• Encourage a second bloom on some plants by deadheading

IMPORTANT: Keep it clean! When removing diseased wood, clean your tools after each cut by immersing cutting blades in rubbing alcohol or wiping with a Clorox wipe.

For more information on pruning hydrangeas, click here.

FAQ: Why does my Manhattan Euonymus have yellow spots?

"I have a hedge of Manhattan Euonymus that gets unhealthy yellow spots on the leaves every year. Why is this?"

Turning the leaves over, you may well find little flat whitish jobs on the underside. You’ll be looking at the males of Euonymus Scale. The brownish females are lurking nearby on the stems. This is an extremely common pest of euonymus. The scales suck sap out of the leaves, producing those lighter spots. Severe infestations can produce a lot of leaf drop. The pest doesn’t often kill a plant as vigorous as Manhattan euonymus, but it can make it pretty ugly.

The most effective sprays are horticultural oil, which suffocates the insect, and insecticidal soap, which kills by destroying the insects’ protective covering. Complete eradication is difficult as it’s almost impossible to cover every surface of the plant. In desperate cases, heavily infested branches can be cut out and destroyed, or the entire plant can be cut down and allowed to resprout if it’s not too late in the season.

FAQ: Why aren't my perennials coming back?

"I plant hardy perennials in spring, they do great all summer and fall, but then they’re dead the next spring. Is it bugs, a fungus or just the cold weather?"

It’s cold, heavy, wet soil rotting out the roots, and it means your soil is too poorly drained. Before you replant, dig in some soil amendments like Soil Conditioner or Landscape Planting Mix to create a better draining site. Your plants will most likely grow happily for you if they get better drainage.

FAQ: What causes the leaves to get spots and drop off my bell peppers?

Bacterial Spot, caused by xanthomonas campestri. This pathogen is found just about everywhere peppers are grown. Hot, wet summers encourage the disease. Unfortunately, even pepper seed can carry the disease so it is almost impossible to avoid. But it can be prevented.

HOW TO HANDLE:
Start by planting resistant varieties. Good seed catalogs list the disease resistance of the types they carry, so start by doing a little homework can go a long way before you buy seeds or plants. Keystone Resistant Giant, California Wonder, and especially Boynton Belle have shown excellent disease resistance for us.

The official treatment is spraying with copper-based fungicide. The unofficial treatment is to use a fungicide containing chlorothalonil, the same product used for Early Blight on tomatoes. Although bacterial spot on peppers isn't listed on the label as a use for this chemical, it works and has been used for this purpose for years by gardeners "in the know."

FAQ: What is eating the leaves of my snap beans?

"Something is eating the leaves of my snap beans and chewing holes in the beans. What is responsible for this?"

A likely culprit is the aptly named Mexican Bean Beetle. These beetles eat the underside of the leaf, leaving an intact surface which dies and gives the leaves a distinctive lacy appearance. Both the adults (which are orangey-brown with black spots) and the cream colored larvae do the damage.

Japanese beetles can attack beans, as well. They chew holes all the way through the leaf, ultimately leaving only the vein structure behind. Control is the same for Mexican Bean Beetles and Japanese Beetles.

WHAT TO DO:
Growing fast maturing varieties sown in spring and fall may help you evade the pest, as they are most active in summer.

FAQ: Why are my tomato plants starting to lose leaves from the bottom up?

"Every year the same thing happens to my tomatoes. At first they grow great but then in early summer they start losing leaves from the bottom up. Eventually the whole plant is trashed and tomato production stops. What is happening and how can I stop it?"

Two words: Early Blight. It's the lucky (and rare!) gardener who doesn't see this problem. The cause is a fungus and control involves several elements.

HOW TO CONTROL:
Garden Cleanup: Be sure to remove as much diseased plant material as possible. At the end of the season, clean up well and don't compost debris. Just throw away all debris.

Crop Rotation: If possible, grow tomatoes on a different site every year, not using the same site for at least three years. However, unless you have a huge garden, this can be pretty difficult.

Staking & Caging: Keeping the tomato plants off the ground helps tremendously, as often the spores linger in the soil.

Mulching: One of the most common sources of Early Blight infection comes from soil splashing on the lower leaves of the plants, either from rain or irrigation. Mulch prevents this. Wheat straw, newspaper, biodegradable plastic, or flattened cardboard boxes work great. Plus, your plants get the advantage of a more evenly moist root zone, which increases yields and reduces fruit cracking.

Timely Fungicide Spraying: Get a fungicide containing chlorothalonil or mancozeb, and spray at recommended rates a couple days after setting your plants out. Then spray every 10 days or so. Spray after rain, too. Keeping up with this spray program will protect your plants all summer and into the fall.