How to Grow Hydrangeas In Different Soil Types

Last Updated on November 14, 2022 by Stephanie

Hydrangeas thrive in friable loam soils and soil with an abundance of organic matter. The soil must retain moisture and be a lightweight structure that drains easily. If the soil is rich in nutrients, it is not necessary to add fertilizer to the soil.

Hydrangeas can thrive in alkaline and acidic soils however this can affect the color of the flowers when its the bigleaf hydrangea ( Hydrangea macrophylla).

Soil pH for Hydrangeas

Hydrangeas can thrive in alkaline and acidic soils, and particularly the Hydrangea macrophylla(commonly called bigleaf hydrangea also known as French hydrangea) can change color based on the alkalinity or acidity in the soil.

Other kinds of Hydrangea with lime or white flowers arent affected in the same way by pH of the soil and their flowers will stay the same color regardless of pH.

If the soils pH is 6.5 or less (acidic) that means the color of the flowers of large leaf hydrangeas is blue. If the soil has pH 6.5 (so or slightly acidic, acidic or pH neutral) then the flowers will be pink.

You can alter the color of the blooms of the bigleaf hydrangea by altering the pH of the soil.

To make the pink flowers blue the most effective method is mixing ericaceous soil (which is acidic in pH at 5.5) in the soil around it as mulch, or simply cut the hydrangea from the soil during winter hibernation and mix the ericaceous compost directly in the soil in which the hydrangea plant is.

This process will require some trial and error, and it can take several months to get the results, so patience is the key!

To make blue flowers pink, youll require an alkaline soil amendment like wood ash or lime, or it could be that you just need regular compost, which is around pH 7.7 once it has fully decomposed (leaf mould and well-rotted garden compost are typically at pH 7.).

You can purchase lime on Amazon that will increase the pH of your soil from acidic to less acidic, acidic or pH neutral (depending on the amount you apply and what the soil pH is to begin with) or you can use wood ash to amend the soil (which is an alkaline).

Garden lime is the choice Id recommend since there are clear guidelines on what amount lime you should add while its much more difficult to determine precisely how much wood ash you will need.

The addition of too many wood ash pieces at one time can drastically alter the soils condition that could alter the availability of nutrients within the soil, so it is recommended to stick with garden lime and follow the directions.

hydrangea bushes

The ideal soil structure for Hydrangeas

A good soil has for it to hold water while allowing for adequate drainage, so that the roots do not sit in the soil that is saturated.

The soils that are rich in organic matter is perfect for hydrangeas since they hold water and create the perfect soil structure that roots can develop and grow into.

Soils with a high amount of organic matter generally are healthy and have an ecosystem of soil that is populated with beneficial earthworms, fungi, and bacteria that all help increase the availability of nutrients within the soil.

Earthworms, in particular, consume organic matter. They create worms casts, which is an extremely concentrated form of nutrients that can be extremely easy for plants to absorb.

Worms also make canals in soil as they make their ways through, creating the space for roots to develop and reduce compaction in hard soils. It also improves drainage and draw air pockets into the soil, which will fuel the beneficial bacteria and helps the roots.

A well-groomed soil that is full of worms can result in an hydrangea in good health that will (as as the other conditions are in place) produce plenty of blooms and healthy leaves.

Sandy Soils for Growing Hydrangeas

The sandy soils pose a problem for the growth of the hydrangeas because water can seep into the soil too fast and then dry out prior to the root of the plant will be able to absorb the moisture, resulting in the dying the hydrangea.

The sandy soils can also be deficient in nutrients, which make them unsuitable for Hydrangea when it comes to producing lush foliage and a large bloom display.

It is possible to make changes to your soil that can, with the right care, enable you to grow the hydrangeas with success.

For hydrangeas to thrive in sandy soil , youll have to amend the plant space with plenty of organic matter. Mixing compost with manure is perfect as both are excellent in retaining moisture. The manure will provide a an important increase in fertility for the soil.

Include as many organic materials as you can, even in the event that it requires replacing some of the soil with sandy. It is necessary to dig the compost to an average depth of 6 inches, and best at least 18 inches in width to accommodate rootstocks of the Hydrangea once it is fully mature.

Applying a layer of mulch each spring will help increase the water retention properties of the soil as well as increase fertility.

Install a 2 inch layer of compost on the soil around the hydrangea. Leave an area of 6 inches in between the mulch layer and the hydrangeas wood to prevent it from being exposed to a persistently damp material that could cause the fungus to develop.

If your soil has been amended by quality garden compost manure, leaf mould, or leaf the soil will be capable of retaining enough water and supply the proper amount of nutrients needed for the hydrangeas to flourish and bloom effectively.

However, Id always water the hydrangeas in areas with sandy soils more frequently. In the summer, the hydrangea in full sun will require daily watering with 2 Gallons of water (9 litres) every time.

Soil Nutrients for Hydrangeas

If youve enriched the soil with organic matter prior to planting your hydrangea, then youre off to a great start to providing the proper nutrients needed to grow an energizing plant that has plenty of flowers.

Applying a regular layer of mulch on your hydrangeas is an excellent way to improve the fertility of the soil and help to improve the soil ecosystem.

In these conditions, your hydrangeas health should be good and have strong blooms.

But if you live in a naturally poor soil, or the roots of the hydrangea are competing for nutrients with other trees and plants (such like pines) its recommended to apply fertilizer to the soil to ensure that the Hydrangea receives all the nutrients it requires.

Hydrangeas can benefit from the general fertilizer for shrubs, but there are certain fertilizers specifically designed specifically for hydrangeas that I would recommend using when there is lots of competing with other root systems in soil.

Specially granulated hydrangea feeds have an additional amount of iron and magnesium to blooming boots and also provide nutrients like potassium, nitrogen and phosphorous to meet their needs.

Growing Hydrangeas in Clay Soil

If youve got loam soil that has around 20 percent clay (the rest is made up of silt 40% and sand 20 percent) This is the ideal soil for the cultivation of the hydrangea. The clay can hold in moisture, while the silt and sand allow for drainage and offer sufficient permeability surface for roots to develop and grow quickly.

If youve got clay soil that is heavy, this could cause issues for the hydrangeas. In clay soils with a lot of clay the water can drain slowly or form Puddles around the roots over long periods of time, which can cause root decay.

Additionally, slick heavy clay can be an extremely difficult substrate for roots to work their way through and grow correctly.

The heavy clay soils that drain slowly must be amended prior to plant and grow hydrangeas.

The procedure is like amending soil to create sandy soils. It is necessary to remove the clay that is heavy and substitute it for organic matter like manure or compost that will allow necessary drainage and will be light enough in its texture to allow the roots to quickly establish themselves.

Be sure to remove all the clay up to about 10 inches. Add sand to the compost mix to ensure that the water doesnt collect beneath the plant.

Digging a hole that is 18 inches in diameter will ensure you that your hydrangeas bud can spread in the dirt and grow quickly without being impeded by clay lumps.

Luckily, clay soil tends to be fertile and is ideal for hydrangeas and it is highly unlikely that youll require any additional feed for your hydrangeas in order to create a beautiful show of flowers each year.

Since clay soil naturally retains water it is possible that you only need for watering your flower once every week during the growing season, but this is contingent on the conditions.

Conclusion

The best hydrangeas thrive in loam soils or in soils which have been amended with organic matter. The soil must be porous and friable in texture to allow for drainage as well as to allow the roots to grow.

It is possible to make some changes for soils that are poor to allow it to be suitable for hydrangeas to grow by adding amendments like manure and compost, which are water-retaining in nature and an excellent amount of nutrients.

Slow draining soils with lots of clay may also require amending with lots in organic material (such like compost) to increase drainage and allow roots to spread and develop.

The clay that is heavy will probably require Sand to be added to the compost mix to make sure that water doesnt get into the soil and cause rot to root systems of Hydrangea.

An annual, regular mulch is essential to ensure the best soil conditions for the hydrangeas.

Hydrangeas dont necessarily require an additional fertilizer if their soil is healthy. However, when the hydrangea is required the potential to be competing for nutrition with lots of other trees and plants within close proximity, then a general fertilizer for plants twice per year is recommended.

Stephanie

Stephanie

Went from an inexperienced gardener to a half-decent one over 10+ years. I cover anything from general indoor plant guides and lawn care, to succulents and flowers. Super happy to share my tips and tricks with you :)