For optimal growth, bloom production, and quality, fertilize three times: In early spring when plants are just leafing out. In early May to boost their flower production for summer. In late June/early July to help your plants finish the summer strong.
Learning how to fertilize hydrangea shrubs is equally as important as the type of fertilizer chosen. Apply a slow-release chemical for shrubs and trees once a year. Depending on the variety, a balanced time-release fertilizer can be applied a few times a year, in spring and early fall.
Balanced granular fertilizers such as Espoma Rose Tone and Holly Tone are good choices. Jobes Fertilizer Spikes are another good option. Avoid using fast-release fertilizers in liquid form on hydrangeas. These products can stimulate growth in the short term but may not sustain the plant for the long haul.
If you over-fertilize, it can burn the root system of your hydrangea bushes and actually inhibit bloom production. For more tips on fertilizer and how to achieve big, beautiful blooms, please click here. My hydrangeas have brown dry spots on the leaves and brown petals on the bloom.
Miracle-Gro Performance Organics Blooms Nutrition
This is an all-purpose blossom booster that's suitable for use on a wide variety of perennial and annual blooming plants, including hydrangeas.
But there's one key aspect of ensuring hydrangeas return bigger and better every year: deadheading. The practice of removing spent flowers from a plant, deadheading encourages stronger, more bountiful blooms later on.
Also, when you do water, after a week or 10 days, water with a water soluble fertilizer such as Miracle Grow, Rapid Grow or Peters 20-20-20. Apply this water soluble fertilizer every second or third watering and see if the plant doesn't do better.
Prune in early spring, just as leaves are beginning to show. Cut branches back by one-half to one-third, cutting just above a node. Next, remove any weak or spindly branches.
However, slow-release is certainly not the only way to fertilizer hydrangeas. A less expensive fast release fertilizer such as a 10-10-10 will work just as well if applied twice during the summer.
Water at a rate of 1 inch per week throughout the growing season. Deeply water 3 times a week to encourage root growth. Bigleaf and smooth hydrangeas require more water, but all varieties benefit from consistent moisture.
Supply the Right Amount of Water. Along with planting them in the right place, properly watering your hydrangeas is essential to bigger and better blooms. "Hydrangeas should be watered deeply several times per week to encourage deep root growth," says Enfield.
Water your hydrangeas in the morning before the heat of the sun is strong enough to quickly evaporate soil moisture. Try to avoid watering at night, which can encourage mold and mildew as the moisture sits through the cool night. Water your hydrangeas through the growing season as well as in late fall.
If you don't prune hydrangeas then they can eventually resemble a tangled mass of woody stems, and the flowers will become smaller and less showy.
Wrap with winter protection.
During the winter, make a DIY A-frame wire cage out of burlap and chicken wire to protect your hydrangea plant. This cage will protect it from winter winds, heavy snowfall, and cold temperatures.
To reduce the size of a hydrangea that blooms on new wood, cut off about one-third of each stem in late fall or early spring before it begins to leaf out. If your hydrangea blooms on old wood, prune right after it has bloomed when the flowers are fading.
Some gardeners report success in turning their hydrangeas blue by applying coffee grounds to the soil. The coffee grounds make the soil more acidic, allowing the hydrangea to more easily absorb aluminum. In addition, fruit peels, lawn clippings, peat moss and pine needles, are thought to have a similar effect.
In warmer regions, feed hydrangeas a second time in June. In all regions, warm and cold, cease fertilization of hydrangeas two months before the average first-frost date in your area. Late fertilization of hydrangeas produces lots of lush, tender growth at a time when plants should be preparing for winter dormancy.
It's best to start adding coffee grounds to the soil months before the blooming season begins, ideally in the late fall. You can repeat the process with your typical fertilizing schedule. With a little caffeine and a lot of patience, your hydrangeas should reward your efforts come spring with the boldest blue globes.
Are the blooms on your hydrangea shrubs fading or turning brown? No need to worry – this is simply a sign that it's time to remove the flowers, a process called deadheading. When you deadhead hydrangeas, you aren't harming the plants at all.
Cut the dead stumps down to their base to completely remove them. This will allow the new growth underneath to have a chance to succeed. Dead and old blooms need to be removed to make room for new buds to come through. Cut the flower head off right above the first few leaves to encourage blooms for the next summer.