Endless Summer hydrangeas grow at a moderate rate. They don't grow too slowly or too quickly, and typically reach their mature size in 3 to 5 years. These hydrangeas produce large blooms lasting up to 8 weeks during the summer months.
The Endless Summer series blooms on both new and old wood, making the plants much more versatile in the landscape. However, if the plants are not properly fertilized in the spring, few if any buds will be produced on the current season's growth.
Shades range from deep blue to light lavender to soft mauve to vivid pink. The more acid the soil, the bluer, and the more alkaline the soil, the pinker the flowers are. Endless Summer Hydrangeas are compact, growing 3-4 feet tall with a 3-4 foot spread.
Endless Summer® Hydrangea will grow to be about 4 feet tall at maturity, with a spread of 4 feet. It tends to fill out right to the ground and therefore doesn't necessarily require facer plants in front.
Fall/Winter Care
Cover the plant with a four-inch layer of organic mulch (wood mulch, leaves, etc.). There is no need to cover all stems to the tip or to cut them back. Covering should be done when fully dormant (around November 30th), or at the same time you would cover perennials in your garden.
"Bigleaf hydrangeas, such as endless summer, should be deadheaded when the first set of flowers sprout from last year's growth in the spring," says Meyers. This eliminates the faded flowers before the next flush appears.
The Endless Summer hydrangea thrives in partial shade and needs well-drained soil with consistent moisture. It does need some sunlight for photosynthesis and flowering potential, but overly hot direct sunlight can scorch the leaves.
Though they are fast growing shrubs, it can take 2-4 years for hydrangeas to reach their full size. Some are faster to mature than others.
Endless Summer hydrangeas grow best in partial sun. A location that receives morning sun and dappled afternoon shade is ideal. If these hydrangeas are planted in full sun, conditions might be too hot and intense for the plants to produce blooms. Planting in too much shade can result in weak stems and fewer blooms.
Most of the varieties in Endless Summer will reach 3-4′ wide at maturity. I would give them at last two feet away from the foundation. Or even a little more if you don't want them touching the house. Summer Crush is the most compact, so you can plant that one a little closer.
Hydrangea blossoms are at their best when they are well watered and well fed. Mulch also provides an evaporation barrier. Keeping your soil moist in the heat of the summer, which is also the flowering season for hydrangeas, will help to maintain the healthiest version of your plant.
Watering and Fertilizing Endless Summer Hydrangea
Hydrangeas plants need to be watered at least once per week. It's best to water them twice weekly when the temperatures are high and conditions are dry. Fertilize your hydrangeas once during the spring or early summer using a slow-release tree/shrub fertilizer.
Cut these stems close to the ground. Remember buds for blooms are produced on old wood and the more old wood you remove the less floral display in the spring and summer. To rejuvenate the hydrangea, remove up to 1/3 of the older living stems down to the ground each summer. This will revitalize the plant.
Endless Summer hydrangeas should be planted in a place that receives morning sun and dappled afternoon shade. "The amount of sun they can tolerate depends on the zone," says Mcenaney. "Endless Summer hydrangeas that are planted in zone 4 can tolerate more afternoon sun than those planted in zone 9."
Fall is the best season to plant hydrangeas, followed by early spring. The idea is to give the shrub plenty of time to establish a healthy root system before blooming. The best time of day to plant is early morning or late afternoon.
As rapid growers—averaging about 2 feet of growth per year—larger varieties of hydrangeas can reach up to 15 feet tall. Applicable in growing zones 3 to 9, hydrangeas are a low maintenance plant that will return year after year with proper care.
A newly planted bush may bloom the first year if it set flower buds while it was confined to a pot, and then not bloom again for a year or two as it settles into the soil in its new location. Instead it is busy growing new roots and branches, instead of flower buds.
In general, as soon as your hydrangea bushes start growing again after the winter, it's time to fertilize. "Just like you and I thrive with a shot of caffeine to wake us up in the morning, Endless Summer hydrangeas bloom best with an early spring application of fertilizer," McEnaney says.
There are a few main reasons that you may not see blooms on your hydrangea bushes: sun exposure, over-watering and over-fertilizing. Endless Summer® hydrangeas prefer morning sun and afternoon dappled shade. If they are planted in full sun, it may be too hot and intense for the blooms to produce.
Provide a layer of organic mulch to help retain moisture, add nutrients to the soil, and protect the plant in the cold winter months. Plant is a full sun to partial shade location, though this plant does best in partial shade. Water frequently, at least once per week. But ensure the soil does not stay wet.
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.
Since Endless Summer® Hydrangeas bloom on last year's growth (“old wood”) as well as the current season's growth (“new wood”), you will get the most flowers by protecting the flower buds on the old wood. To do this, do NOT prune or cut back your shrubs after August 1st.
“You're looking for a slow-release granular fertilizer that is labeled 'bloom boost,'” says Endless Summer expert Ryan McEnaney from Bailey Nurseries. Bloom boost fertilizers such as Flower-tone ($10, Ace Hardware) have a higher level of phosphorus, the nutrient that promotes flower formation.