It is a Hydrangea World!

Good gardening friend Paul Parent of the Paul Parent Garden Club sends out a great newsletter every week with pertinent gardening topics. I encourage you to go to his website to sign up for his newsletter. Paul can also be heard every Sunday morning from 6 AM to 10 AM at his website or at WBACH (104.7 FM) every Sunday morning from 6 AM to 9 AM. Paul recently sent this article out called "The Blue Hydrangea and the Pink Too " (I occasionally add a few comments in italics) and here it is:

This past weekend, I spent time on beautiful Cape Cod doing a live radio broadcast at Snow's Home and Garden in Orleans, and I was just overwhelmed with all the beautiful blue hydrangeas growing at most homes all over Cape Cod. I can remember that just over 10 years ago the blue hydrangea was the plant that everyone talked about when they came back from a Cape Cod vacation...and they just had to have one in their garden. Along the coast north to Boston they did beautifully (if the winters were not too severe) but if you lived inland and north the plant grew fine but flowers were few on the plant. The reason was that the best variety at that time, called the 'Nikko Blue' hydrangea, only made flowers on the "old wood," the branches on the plant that were made the previous summer. If the winter was severe, the plant had much die-back of the old wood, so flower production was minimal.

In the late 1990s, Bailey Nurseries in Minnesota found an unusual blue hydrangea plant and started growing it in the nursery's trial gardens. Dr. Michael Dirr from the University of Georgia was visiting the nursery and spotted this unusual plant; he took cuttings back with him for further research and testing. Thanks to Dr. Michael Dirr and Bailey's, we now have this new plant for our gardens. This new blue hydrangea is called "Endless Summer," because it was able to flower on old wood like the 'Nikko Blue' Hydrangea but, unlike the 'Nikko Blue,' it is also able to make flowers on the new growth made during the summer months. This made the plant a true perpetual-flowering hydrangea--the first of its type.

The original hydrangea, 'Nikko Blue,' flowered from late June to middle or late August. This new hybrid made new growth all summer long so it was able to flower until frost in late September, or early October in warmer climates. This gave the plant 8 to 10 weeks of additional flowering time. This new hybrid could also thrive in colder climates, zone 4 to 9, and was hardy to minus 20 to 30 degrees below zero. The 'Endless Summer' hydrangea will grow from southern New Hampshire, Vermont, and Central Maine south to Florida, with some protection in colder locations.

The first thing to remember about blue hydrangeas is to NEVER Prune them in the fall of the year. Pruning the plant in the fall when it becomes dormant will cause problems with every branch you prune, because it has an open wound that will lose moisture all winter and the branches you cut back will slowly dry up and die. In the spring you can cut them back a bit to control the height of the plant and encourage new growth to form from the root system. If you cut back the plant to the ground, you are removing all the flower buds on those branches and the plant will not flower. Remember, old wood has flower buds on it and if you remove all that old growth you are removing the potential flower buds for the coming summer. In the spring the branches look like dead sticks but they are alive; leave them alone!

The Awesome Endless Summer Blue Hydrangea!

The new 'Endless Summer' hydrangea loves to be pruned lightly in the spring to control height and spread. If you can prune faded flowers on the plant during the summer, you will encourage additional flower buds to form on the new growth made during the remaining weeks of summer. Do not be scared to cut branches filled with flowers from the plant and put them in a vase of water for your enjoyment. This selective pruning will stimulate new growth on the plant, and in just a few weeks new flowers will form on the new growth being made on the plant.

The 'Endless Summer' blue hydrangea will grow 3 to 4 feet tall and just as wide and in just 2 to 3 years, once planted in your garden. Once the plant has matured and has become well established in your garden, winter protection is less required. The flowers of this new blue hydrangea will grow 4 to 8 inches in diameter, and like all mop head type hydrangeas, 3 to 6 inches tall. Each flower is made up of fifty plus individual flowers about one inch wide; the flowers have five petals arranged in a circular form with a flat center. The flowers can be cut for your favorite vase, dried when in peak color by removing the branch from your plant, stripping off its foliage and hanging it upside down in your garage to dry for a couple of weeks. Dried cut hydrangeas will last inside your home all winter long in a vase or when used to make a wreath.

Plant the blue 'Endless Summer' hydrangea in full sun to partial shade garden for the best flower production on the plant. The plant will grow best in a sandy soil that is well drained; keep the plant out of wet areas or where water tends to collect after heavy rains. This type of garden will form ice and the plant will have a lot of winter dieback during the winter months. If your soil has a bit of clay, be sure to blend peat moss, animal manure or compost to break up the heavy soil before planting. If your soil is very sandy use the same products to help hold moisture in the soil in the root growing area, along with Soil Moist granules.

Because the plant has large leaves and uses a lot of water, it will wilt easily on hot sunny days until it is well rooted in its new home in your garden. Mulching around the plant in your planting bed 2 to 3 inches thick with bark mulch, compost, pine needles or shredded leaves will also help hold moisture in the soil and control weeds during the summer months.

This type of mop head hydrangea is the ONLY plant whose flower color can be changed by controlling the acidity of the soil it grows in. If you keep the soil with a pH of 5.5 or lower, your flowers will range from a clear blue to deep purple, depending on acidity of the soil. This can be accomplished by using aluminum sulfate fertilizer at the rate of one tablespoon per gallon of water applied to the plant every couple of weeks.

If the flower gets to be too deep of a blue color--or even purple--apply a couple of handfuls of limestone or wood ash every spring and fall. If you want to make them more pink than blue, add heavy applications of wood ash or limestone several times during the growing season to raise the soil pH to 6.0 or higher. If you use a high phosphorus fertilizer, it will block out the aluminum fertilizer in the soil from entering the plant, helping to keep the plant on the pink side also.

Fertilize spring and fall with an acid-type fertilizer such as Holly-Tone by Espoma to encourage uniform growth and flower bud production. When planting new plants in your garden be sure to water every week during the summer for the first two years as plants are slow to get established in your garden. All I want you to remember is that if you live where the winter months are cold, always select the 'Endless Summer' blue hydrangea and never the 'Nikko Blue,' if you want flowers during the summer months. The extra $5.00 will insure that you always have flowers on your plant. Enjoy!

Thanks to Paul Parent!

Mike Skillin

Skillin's Greenhouses

July 21, 2011