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.
Aim for late spring, well after any danger of frost has passed, or early fall, when night temperatures usher in cooler air. If you garden in a region where the ground freezes, get plants into the ground at least six weeks prior to fall's first killing frost.
The months of both spring and fall are best for planting hydrangeas, so long as the weather is mild. In spring, this should be after frost season, and in fall, before it begins again. If you need to plant in other months, avoid those that are very hot or very cold.
To prepare hydrangeas for winter in colder areas, add a thick layer of mulch around the base of the plants to protect the crown and roots from freezing temperatures.
In Ground: Hydrangea are easy to grow in most any moist but well-drained soil of average fertility.
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.
To loosen the soil, mix dehydrated cow manure, garden compost or peat moss (up to 1/3 concentration) into your pile of topsoil. Make sure the peat moss you get is either baled sphagnum or granular peat.
4. No need to prune. If you trim your plants in fall or winter, you may mistakenly remove flower buds for the following year on bigleaf and oakleaf hydrangeas. Leaving the old flower heads on the plants will also add some interest to the winter landscape.
Lay down 6–8 inches (15–20 cm) of mulch around the plant base. Hydrangeas require a thick layer of mulch to protect them properly throughout the winter. Scatter your mulch materials to cover the ground around the base of your plants. Make sure that the mulch is at least 6 inches (15 cm) high.
Best Time To Plant Hydrangeas
They can be planted at any time of the year. However, to get good results, keep these considerations in mind: Whenever possible, plant in early summer or fall. Don't plant in early spring when frosts are still possible.
Most common hydrangeas prefer a partial sun location - ideally receiving sun in the morning hours and shade in the afternoon. The reblooming Endless Summer® Hydrangea series prefers part shade. These include BloomStruck®, Endless Summer®, Blushing Bride®, and Twist-n-Shout®.
Where to plant hydrangeas. Hydrangeas do best in moist, well-drained soil and dappled shade – not too sunny and not too shady. Avoid south-facing positions, especially if the soil is very dry. For a very shaded spot, such as a north-facing wall, grow the climbing hydrangea Hydrangea anomala subsp.
However, stop deadheading hydrangea shrubs in mid to late fall, leaving any spent blooms in place. This not only provides winter interest, but also ensures you don't remove the buds that will become flowers next spring.
Prune these hydrangeas only after bloom in the summer and not in the fall. Old wood hydrangeas start developing their bloom buds for next year in August and September. If you don't prune your hydrangeas real soon, then it is better to wait until next year. Otherwise you won't have any blooms next spring.
In late winter or early spring, these shrubs can be cut all the way back to the ground. Smooth hydrangeas will produce much larger blooms if pruned hard like this each year, but many gardeners opt for smaller blooms on sturdier stems.
Without going through the deadheading process, hydrangeas will not produce as many flowers and the few produced may not grow as big to their full potential.
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.
Prune back stems to just above a fat bud — called a heading cut — in fall, late winter or spring.
While some plants bloom on new growth, others primarily set flower buds on old wood. Regardless, it is best to wait to prune all hydrangeas until spring. In the fall, hydrangeas (and all trees and shrubs) are in the process of going dormant. They do not produce very much new growth until the following spring.
To grow hydrangeas in planting beds, focus on improving the native soil. One simple way to do that is to combine equal parts existing soil and Miracle-Gro® Garden Soil for Trees and Shrubs. In warmer regions (zones 7 and warmer), where winter tends to be mild, you can also grow hydrangeas in containers.
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.
For best results when planting hydrangeas, follow these steps: Create a hole twice as wide as the plant's root system, and about six inches deeper than the plant's pot. Break up the soil a bit before you plant to help the roots easily establish themselves.
East Side. The east side of the house is the best planting location, as it gets the morning and afternoon sun. This is the best side of the house for your hydrangeas, traditionally.