How to Plant Hydrangeas in the Ground or in Containers

Planting Hydrangeas in the Ground

Wait until the fall or spring to plant hydrangeas. Hydrangeas are active and blooming throughout the summer months, and they’re more likely to survive if you plant them while they’re dormant. Plant before the first frost in the autumn if you want your hydrangeas to grow stronger roots. Otherwise, wait until after the last frost passes in the spring. Hydrangea bushes typically grow best in USDA zones 3 to 9, but it varies on the specific cultivar you’re growing. Check a USDA zone map to find out what hardiness will grow best in your area.

Choose a planting spot with loamy, well-draining soil. Growing hydrangeas works best in soil with sand and silt that drains quickly but still retains a little water. Look for a planting space and check the soil to make sure it doesn’t contain a lot of clay. If you do need to amend clay soil, mix in organic matter like compost or manure to help improve the drainage. To test your soil’s drainage, dig a hole that’s 12 inches (30 cm) deep and 12 inches (30 cm) wide. Fill it with water and wait a day. Then, fill the hole with water again. Check the hole after an hour. If the soil drains between 1–3 inches (2.5–7.6 cm), then the soil is properly drained.

Pick an area that gets partial shade or full sun during the day. Find a place in your yard or garden that gets at least 2 hours of direct sunlight in the morning and shade throughout the afternoon. If you don’t have any partially shaded areas, hydrangeas can tolerate areas that get around 6 hours of direct sunlight as long as you keep the soil moist. Oakleaf and bigleaf varieties of hydrangeas are more prone to drying out in full sun because they have more foliage. If you only have full sun areas in your yard, try smooth or panicle varieties instead.

Dig a hole 1–2 ft (0.30–0.61 m) larger than the root system. It’s easiest to plant hydrangeas that are already potted and in bloom rather than starting them from seed. Use a shovel to dig a hole in the ground in your planting spot so it’s a few feet wider than the root system on your hydrangea. Make the hole about as deep as the current pot. Hydrangeas can spread up to 6 feet (1.8 m) during the growing season, so try to keep them spaced about 5–6 feet (1.5–1.8 m) apart if you’re planting multiple bushes.

Place the hydrangea in the hole and firm the soil around it. Carefully pull the hydrangea out of its current pot and break apart the soil around the roots. Set the root ball in the middle of the whole so the base of the plant is level with the soil. Fill in around the root ball with your soil and pat it down into a firm mound around the hydrangea’s base.

Water the soil thoroughly. Once you’ve planted your hydrangea in the ground, use a watering can or a soaker hose to water the soil directly. Let the water soak into the soil to help remove air pockets and make your hydrangea less stressed from transplanting it. Stop watering before it starts pooling on the soil’s surface. Try not to get any water on the hydrangea leaves because it could cause spots of discoloration or disease to form.

Apply a 2–3 in (5.1–7.6 cm) layer of mulch around your hydrangeas. Spread the mulch around the soil into an even layer, making sure it doesn’t directly touch your hydrangea’s stem or trunk. Mulch helps retain moisture in the soil so your hydrangea is less likely to dry out or wilt from the heat.

Planting Hydrangeas in Pots

Wait until spring or fall to pot your hydrangeas. If you want to grow hydrangeas in a pot, wait until they’re dormant in the early fall or late spring. Wait until the last frost passes in the spring, or plant before the first frost in the fall so your plants don’t get damaged. You may try to pot up hydrangeas during the summer growing season as long as you keep the soil moist, but it may cause more stress to your plant.

Choose a 16–24 in (41–61 cm) weatherproof container with drainage holes. Hydrangeas grow large root systems, so planting them in a large pot right away gives them space to spread out. Pick a pot that’s labeled as “frostproof” or “weatherproof” so it doesn’t break when the seasons change. Make sure the pot has a few drainage holes at the bottom so excess water can drain out. Avoid using terracotta or clay pots because they may crack or break from temperature changes in between seasons.

Place the pot in an area with morning sun and afternoon shade. Find a place that gets a few hours of sun during the morning and shade throughout the afternoon so your hydrangeas don’t dry out. Because hydrangea pots can get pretty heavy after you fill them with soil, position the pot where you want to keep it first.

Fill the bottom of the pot with a mix of potting soil and compost. Pour in fresh potting soil into your pot so it’s about half-full. Then, pour in a 1 in (2.5 cm) layer of compost. Use a trowel to stir the compost into the soil so it’s thoroughly mixed. Avoid using garden soil for potted hydrangeas because it’s too dense for plants to grow strong roots.

Set the hydrangea into the middle of the pot and fill in the soil. Carefully pull your hydrangea out from its original pot and break apart some of the soil around the root ball. Place the hydrangea in the center of the pot. Pour potting soil in around the edges of the root ball, and fill it up to the base of the stem so your hydrangea is at the same depth as it was in the original pot. Leave about 1–2 inches (2.5–5.1 cm) between the soil surface and the pot’s lip so nothing spills out when you water your plants. Alternatively, you may grow hydrangeas from cuttings taken from an existing plant. Cut off a 5–6 in (13–15 cm) branch that didn’t flower and remove the leaves from the bottom nodes. Dip the cutting into rooting hormone and stick it into the pot. Water and cover the plant with plastic so roots form in 2–3 weeks.

Water your hydrangea until it comes out of the drainage holes. Use a hose or watering can to wet the soil directly and give it a good soak. Wait for the water to drain through the soil and come out from the holes in the bottom of the pot. Then, water the soil one more time to remove any air bubbles and help the roots grow in. Try to avoid getting water on the leaves because it could cause yellow or discolored spots.

Add a 2 in (5.1 cm) layer of mulch on top of the soil. Spread the mulch evenly over the soil, but make sure that none of it touches the stem directly. The mulch will help the soil retain its temperature and moisture levels so strong, healthy roots grow inside the pot.

Caring for Hydrangeas

Give your hydrangeas 1–2 in (2.5–5.1 cm) of water every week. Check the soil’s moisture level by sticking your finger into the ground up to your first knuckle. If the soil feels dry, then use a watering can, soaker hose, or drip irrigation to provide water for your hydrangeas. While most hydrangeas will do well with 1 inch (2.5 cm) of water each week, you may need 2 inches (5.1 cm) if you live in a dry, arid climate. When you’re watering hydrangeas in pots, keep adding more until you see the moisture drain out from the holes in the bottom. Water your hydrangeas every week throughout the season, and only stop once the ground freezes.

Apply slow-release fertilizer in late spring and midsummer. Whether you’re growing hydrangeas in the ground or in a pot, spread a 5-10-10 fertilizer over the soil, following the measurements and instructions on the packaging. After you apply the fertilizer, immediately water the soil so the nutrients can soak in and get absorbed by the roots. Reapply the fertilizer again in the middle of summer to continue getting blooms throughout the season. Avoid applying fertilizers after later summer because they may stress the plant while it goes dormant. Steer clear of fertilizers high in nitrogen because they promote more growth from the leaves instead of the flowers.

Use insecticidal soap to control any pests crawling on your plants. Hydrangeas are susceptible to aphids, weevils, and beetles that may try eating the leaves or stems. Start by spraying your hydrangeas with a blast of water from your hose to try knocking the insects off first. If you still notice a problem, then apply the insecticidal soap directly to the foliage in the spring. Try to avoid using insecticides while your hydrangeas are in bloom because you may accidentally harm beneficial pollinators.

Prune old or dead branches from your hydrangeas in the spring. Before your hydrangeas start to bloom, look for any dead or damaged branches on your plant. Start by deadheading any spent blooms that are still on the plant by cutting them off with a pair of pruners. Cut any dead branches off as close to the base of the plant as you’re able to to help stimulate new healthy growths during the season. If you’re not sure if a stem is old or dead, scrape the bark off the stem with a knife. If the stem looks green underneath, then keep it because it’s a healthy growth.

Cut hydrangea blooms in the morning to display and dry the flowers. Water your hydrangeas the night before you plan on cutting blooms so they’re fully hydrated. Go out in the early morning and cut healthy blooms that are fully open and flowering. Use pruners to make an angled cut just above a leaf node, and remove all the leaves from the stem. Put cut blooms in a vase with cold water to preserve them.

Wrap hydrangeas in burlap during the cold winter months. If you live in an area that has harsh, cold winters, prepare the hydrangeas by covering them entirely with burlap to keep them from getting wind-damaged. Alternatively, attach burlap to posts around your hydrangea plot to make a “cage” or protective screen. For additional protection, cover your hydrangeas with 18 inches (46 cm) of straw or leaves to keep your hydrangeas from freezing. Cold temperatures and wind can damage buds that are already forming and may prevent your hydrangeas from blooming the following season.

Adjust the soil pH to change the colors of the blooms. The color of hydrangea flowers depends on the chemical makeup in the soil, and you can easily make adjustments to get the color that you want. Use a pH probe to test the current levels of your soil. Raise the soil pH by adding lime or lower the pH by mixing in sulfur. For blue hydrangeas, keep the soil pH between 5.0 and 5.5. To make purple hydrangeas, adjust the pH between 5.5 and 6.0. For pink hydrangeas, maintain a soil pH of 6.0 and up.