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Whether you call them Hydrangea Macrophylla, House Hydrangea, French Hydrangea,, or Mopheads, growing Hydrangeas in the home garden can be an enjoyable experience. They are lovely, whether used as single plants or in mass, such as in a hedge, or border.
Growing Conditions for Hydrangeas
Hydrangeas grow best in partial shade to full sun. They prefer morning sun and afternoon shade, especially in hot areas
Hydrangeas need a lot of water. In fact the word “Hydrangea” comes from the Greek for “water tub”!
They grow best in rich soil, so dig in a lot of compost, and other organic matter, when you plant them, and mulch well.
Fertilize liberally in the spring, in May in the South, and again in August. Wait until June to fertilize in northern areas. Use a good balanced, slow-release, fertilizer and apply ¼ cup around the base of a very small plant, and 1-2 cups around a very large plant. Spread out to drip line, but don’t get it next to the trunk. Mulch with homemade compost to cover roots. Never fertilize a plant that looks sick or wilted, it will just stress it more.
You can propagate from softwood cuttings in June. Take a 6″-8″ tip cutting, strip off the bottom leaves, dip end in rooting hormone, then stick about one inch deep in sterile
moist sand, vermiculite or sphagnum moss. Create a mini green house over plants with plastic and place in bright light, not full sun, until roots form. Or, you can just root them in water. Again, place in bright light away from full sun until the roots form.
1. Dig a hole 2 times as deep and wide as the root ball. Break up soil in the hole and mix in 1 inch compost.
2. Remove from container and loosen soil around outside of root ball.
3. Set in hole so plant is at same level it was in the pot, you may need to add dirt back into the hole to raise it up.
4. Fill in hole, around plant, with the soil and pack gently. Water well to remove air pockets. Mulch well with compost.
5. Early fall is the best time to plant new Hydrangeas.
In Spring, prune back old or damaged growth, and old flower stems. Don’t cut new shoots, they are where the new blooms will be.
In late summer, after blooming, prune to just above the next outward facing bud.
For larger flower clusters, thin plant down to half the number of stems.
Problems with Hydrangeas
Powdery Mildew—evidenced by white powder on leaves, which then turn yellow and wilt. Treat by removing infected parts and spraying with a fungicide.
If the plants aren’t blooming well, it could be due to:
1. Winter kill. The buds form on the previous years growth, and can be killed off if temps drop below 25 degrees Fahrenheit. Protect when harsh weather is expected.
2. Too much shade. They prefer partial to full sun, preferably morning sun, with shade during the hot afternoons.
3. Poor Fertilization.
You can can change the color of the blossoms, by changing the acidity of the soil.
Add Aluminum Sulfate to make the soil acid for Blue flowers. Or, add Lime to make the soil alkaline for Pink flowers.
You will need to repeat the process 2 or 3 times over the growing season and continue it as long as you want the change to continue. It may take a year or two to see the results you want. This doesn’t usually work on the white varieties on Hydrangeas.
Reprinted with permission.
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