Hydrangeas have long been popular shrubs, revered for their large flower heads that give a decorative pop of color to the landscape or as cut flowers. If you love them and want to incorporate them into your garden, you may be wondering when to plant hydrangeas for the best chance of success.
Growing hydrangeas is generally easy, but planting shrubs at the wrong time can make the process much harder. The most common varieties bloom from mid-spring into early fall, but the best planting time doesn’t necessarily align with the blooming or growing season.
The warm summer months are often the times you want to get out and enjoy the garden. But if you’re interested in planting shrubs like hydrangeas, this isn’t the time to do it. Keep reading to learn when to plant hydrangeas for shrubs that will bloom and thrive for years.
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Best Time to Plant Hydrangeas
Most flowering perennials and shrubs are best planted when the plant is dormant, not during the growing season. As perennial bloomers, you should ideally plant new hydrangeas in the fall when the shrub is in stasis.
The same applies for when to transplant hydrangeas that are already situated elsewhere in your garden. This allows the root system several months to establish itself before it needs to expend energy on blooms in the spring.
Plant hydrangeas when the shrub is not completely dormant, but close to it. In other words, when the hydrangea is not using energy to push out new foliage or blooms and is nearing dormancy, but is still actively growing enough to form new roots. This typically occurs in fall.
But when exactly do you plant hydrangeas in the fall? Timing varies according to the different types of hydrangeas, but even more important is your specific location. Plan on planting when the heat of summer is waning and the nights are cooling, and there are still 6 weeks before your region's first frost date.
There are many benefits of planting hydrangeas in fall, but proper timing is everything. Gauging the correct planting time of 6 weeks prior to the annual first frost for your area will allow the hydrangea ample time to grow a strong root system. It will also help in avoiding transplant shock due to cooler soil and higher amounts of precipitation in fall.
Second Best Time to Plant Hydrangeas
The next best time to plant hydrangeas is early in the spring before bud break when the soil is workable. Again, timing is key. You want to plant your hydrangeas after your last frost date when there is no further danger of freezing in your area, but you still have 6 weeks of mild weather for the shrub to acclimate before temperatures start rising.
The problem with planting in spring rather than fall, is that sudden temperature changes can catch you unawares. We’ve all been through it. One day it’s cool and drizzly and the next, temperatures soar and there’s not a cloud in sight. Early warm temperatures can damage the health of newly planted hydrangeas.
Warmer temperatures send a signal to the plant to put all its energy into producing foliage and buds instead of focusing on root growth. This can lead to transplant shock, especially if a frost or two sneak in afterwards.
That said, spring planting may work more favorably for some varieties of hydrangeas. For instance, mophead hydrangeas and lacecap hydrangeas bloom on old wood which means that winter weather can severely damage buds. Harsh winter cold is one of the most common reasons for a hydrangea not blooming. Spring planting can circumvent this issue and give the shrub time to acclimate.
Worst Time to Plant Hydrangeas
The worst time to plant hydrangeas is in the middle of summer; during the high heat of the season. This could be a disaster. The high temperatures and full sun will likely put the plant into shock, in which case it won’t be able to settle into its new spot.
It isn’t impossible, however, to plant a hydrangea during summer. Plant it in a shaded area or an area with some morning sun then shade the rest of the day. You can also use a sun shade like this tent-like shade and bug cover from the Home Depot. Be sure to also keep the soil consistently moist and follow the tips below.
Tips for Success When Planting Hydrangeas
To grow the healthiest, most vigorous and prolifically blooming hydrangeas, you need to follow some basic rules. First, plant either in the fall or spring as detailed above. Select a variety of hydrangea that is suitable for your USDA planting zone and for which you have the correct sun and shade exposure.
Dig a hole that is at least twice as wide as the nursery pot the new hydrangea arrived in and as deep as the root ball. Don’t mess with the roots too much. Leave them undisturbed.
The soil should be well-draining and fertile. If needed, amend the soil with plenty of organic matter. A soil test can tell you if you need further amendments to the soil like for drainage or to adjust the pH.
Most hydrangeas thrive in soil with a pH of 5 to 6.5. Though, if you’re trying to grow either blue or pink flowers, you can change your hydrangea color with other soil amendments or fertilizers depending on your desired results.
Once the hydrangea is in the ground, give it a thorough watering. In the absence of rain, continue to give the shrub an inch (2.5 cm) of water weekly. This watering hose nozzle that’s a best seller on Amazon makes it easy to keep newly planted hydrangeas hydrated.
Frequently Asked Questions
Can you plant hydrangeas in the fall?
Yes, in fact fall is the best time to plant hydrangeas. Make sure you wait until your last annual freeze has passed, but you still have a good 6 weeks of cool and wet weather. This helps the plant to acclimate and the root system to grow before it begins producing foliage and buds.
What month is best to plant hydrangeas?
The exact month to plant hydrangeas depends on where you’re located. If you want to plant in the fall, plan to plant 6 weeks before the first annual frost for your area.
If you want to plant in the early spring, make sure to plant when all danger of frost has passed yet you still have 6 weeks of cool, wet weather that will allow the plant to acclimate and grow a sturdy root system before pushing out new leaves and buds as temperatures warm. Knowing your USDA growing zone will help you to determine the correct dates or contact your local extension office.
