Hydrangeas can grow and produce luxuriant foliage and beautiful flower displays in pots.
However there are some specific care instructions for growing hydrangeas in pots (rather then in the ground) that you need to be aware of in order to get the best out of your hydrangea.
To grow hydrangeas in pots it is essential that you:
- Choose the appropriate pot (Larger terracotta pots retain water best)
- Use the right soil for planting (the soil needs to hold moisture yet be free draining)
- Fertilize your hydrangea appropriately
- Care for potted hydrangeas over winter
- Know how to prune potted hydrangeas
- Be aware potted hydrangeas need significantly more water then those in the ground
The Optimal soil for Hydrangeas in Pots
Using the right soil or compost for growing potted hydrangeas is essential. Hydrangeas need a soil structure that:
- Will absorb and hold moisture yet…
- Let excess water drain through so the roots aren’t water logged
Therefore it is important to pot your hydrangea in plenty of organic matter. Leaf mould or garden compost is best; however commercial multi purpose compost will also be suitable.
Leaf mould and compost have an exceptional capacity to hold water which is perfect for hydrangeas as they are very heavy drinkers.
Leaf mould and compost retain a structure that allows water to drain through and it is loose and friable enough for the roots of your hydrangea to establish into the so they can access the water and nutrients they need.
The most common reason potted hydrangeas do not survive is because they are in soil that is too dry. Plant your potted hydrangea into generous amounts of compost and they will be far more resistant to drought.
Hydrangeas can Take full Sun (but Prefer Some Shade)
Hydrangeas are most happy with sun in the morning and some shade in the afternoon. Direct morning sun is best for hydrangeas as this will promote flowering and larger blooms but some shade in the afternoon is appreciated as it gives the plant itself and the soil some respite from intense sunshine.
Potted plants are more vulnerable to the drying effects of hot summer sun as the hydrangea will be naturally more exposed then planted hydrangeas that are in the ground. Afternoon shade will lower the rate of evaporation from the soil and transpiration from the leaves to stop your hydrangea from drying out.
If your hydrangea is in full sun all day then you will need to keep the soil moist, consistently. Bigger pots that contain more organic matter have a greater capacity to retain water which is essential to prevent your hydrangea from drying out.
Hydrangeas in full sun will need watering every day on the hottest days so monitor them closely when the temperature soars!
Hydrangeas can grow in dappled light and partial shade but do best when they receive a few hours of direct sunlight.
Water Hydrangeas According to the Conditions
You will need to water, potted hydrangeas according to the particular conditions of your garden.
Hydrangeas in pots will need far more water then planted hydrangeas as they have they have a limited area from which to draw water and the sun can heat the pot they are in which increases evaporation from the soil.
Water hydrangeas with 1-2 gallons (4 to 8 litres) every time you water.
Potted hydrangeas in full sun will need watering every day in the summer. Hydrangeas that receive shade in the afternoon will naturally be able to retain more water and will only need watering 3 times per week in summer. Hydrangeas that are in partial shade or dappled light may only need watering 2 times per week.
It is best to water hydrangeas in the morning as this will charge the plant with the water it needs and prevent soil being too dry during the hot summer days.
Hydrangeas need 1-2 gallons of water in one soak rather then just moistening the first few inches of the soil every time you water.
Alternatively you can water the plant with a soaker hose hooked up to an irrigation system to make sure all the soil is thoroughly moistened in the hottest weather.
This will encourage the roots of your hydrangea to grow deeply into the soil and establish nicely.
When watering with a can or hose, water the pot slowly to make sure the moisture is being fully absorbed into the soil. This may mean that you have to pause every now and then before resuming watering.
In the first month of planting your hydrangea in its new pot you will need water the plant as often as once per day for the first month. Watering thoroughly is crucial in the first month whilst the hydrangeas root system becomes established in its new home.
Hydrangeas can vary significantly is size depending in the species but larger hydrangeas will need more water then the smaller varieties.
Choose the Best Pot for the Job
The pot for your hydrangea should be ideally both functional and stylish so that it looks good on your patio.
Choosing the right pot for Hydrangeas checklist:
- Larger pots do not dry out as quickly. Large pots are less vulnerable to the drying effects of the sun and exposure to wind. They can also contain far more organic matter which gives your hydrangea more soil from which to draw up moisture and avoid the effects of drought during the summer.
- The pot must allow free drainage. Some decorative or improvised stylish pots do not have drainage holes in the bottom and therefore collect water. The roots of your hydrangea will not tolerate water logged soil and be will suffer from root rot. Just one or two holes in the bottom of your pot will be enough for good drainage. A layer of gravel in the bottom will ensure the hole doesn’t become blocked by compacted soil and will allow water to drain away freely.
- Generally speaking the larger the pot the better. Pick a pot that is significantly bigger then the pot that it came in from the garden centre. Hydrangeas do not like small pots as they can restrict root growth and make it more difficult to access the water and nutrients that the plant needs to thrive.
- Thicker terracotta style pots retain water better then plastic or metal pots. Hydrangeas can grow well in thinner metallic pots but thick terracotta doesn’t absorb heat as readily as a thinner metal or plastic pot which helps to stop the soil from drying out. A thicker pot will help keep the roots cooler and keep the soil moist which is exactly the conditions hydrangeas love.
If your have something to elevate your pot off the ground slightly (such as plant pot feet) then this will aid excess water from escaping the pot without pooling in the bottom. This is not always necessary depending on your particular pot or if the pot is placed on gravel landscaped surface.
Importance of Fertilizing Hydrangeas in Pots
Nearly all potted plants will benefit from a fertilizer in the spring and summer months as they naturally have a more limited access to nutrients then garden plants.
A good fertilizer will encourage healthy growth and far more beautiful flowers for you to admire and fortunately hydrangeas are not particularly fussy feeders.
A general all purpose plant fertilizer will do just fine all through you can buy specifically formulated hydrangea granulated feeds that you can purchase on amazon. These formulations only need to be applied twice a year, once in the spring (March or April) and then again in the summer (July).
This will take the guess work out of fertilizing your hydrangeas as the formula has the correct nutrients at the appropriate concentrations for your plant to produce beautiful flowers.
I must emphasize the importance of following the specific manufactures instructions when applying fertilizer. Too much fertilizer will burn the roots and kill plants. Always go with a cautious ‘less is more’ approach and you cannot go wrong.
Never apply fertilizer too late in the season (after August 15th) as this will promote new growth just as your hydrangea is preparing for its winter dormancy.
Fertilizer is more important in potted hydrangeas as you can’t add lots of organic mulch to the same extent as you can with hydrangeas that are planted in flower beds.
Move Potted Hydrangeas Inside over Winter
The benefit of potted hydrangeas are that you have more control over how to protect them in winter. Logic would suggest that if you have established planted hydrangeas your garden then your potted hydrangea should be fine over winter too.
However roots are more exposed to the cold whilst in pots then they would be if they were in the ground.
Ideally you should take your potted hydrangeas inside over winter to protect them form the coldest months. This can be into a greenhouse where the temperature drop is less severe or perhaps into a garage where they will not have to persistently endure heavy frosts.
Potted hydrangeas do not need too much water over the winter as they are in a state of dormancy, so give them a drink once per week with around 1 litre (2 pints) of water. It is more important that you do not let the soil dry out completely.
Protecting your hydrangeas over winter will give them a head start the following spring, so place your pot back in your garden or on your patio when the weather warms in the spring. Don’t worry about the occasional late frost as hydrangeas are cold hardy enough to take it in their stride.
Pruning your Potted Hydrangea
Pruning a potted a hydrangea is no different to pruning any hydrangea. However I always feel pruning is best explained with a visual guide so check out this video on YouTube that explains what you need to know about pruning hydrangeas.
Plant your hydrangea in a large terracotta pot to help maintain the right balance of moisture in the soil. Make sure you use a good compost or potting medium that retains water well, but allows for good drainage (so the roots aren’t water logged).
Water your hydrangea appropriately for the conditions that it is in. Potted plants will need more water then hydrangeas that are planted in the ground. If it is excessively hot then potted hydrangeas may need watering every day.
Care for potted hydrangeas over winter by placing them in a green house or garage. There is less of a need to water during the hydrangeas winter dormancy but make sure the soil doesn’t dry out completely over the winter.