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Are Hostas Good Under Trees?

The natural shade from the trees may at first glance seem like a great place to plant shade-loving plants. However, many gardeners wonder, can I plant hostas under trees?

Hostas are good under trees. To be successful, dig a hole under a tree by slightly pruning the roots of the tree. Plant only large hosta varieties. Be sure to mulch and fertilize the hosta after planting.

Are Hostas Good Under Trees

Type of tree Will a hosta grow under this tree?
Maples Not recommended. Maple roots are very aggressive and it is almost impossible to grow other plants under their canopy.
Willow Not recommended. Willows have thin roots that form a dense carpet. In addition, these plants quickly dry out the soil around them.
Walnut Not recommended. Walnut releases a toxin (juglone) that can cause significant damage not only to hostas but also to many other plants.
Oak The superficial roots of oak do not interfere with the growth of other plants around. However, growing hostas in such conditions requires additional care.
Conifers (Pine, Spruce) There are many examples of the successful cultivation of hostas under coniferous plants. This is especially true of pine, which has a suitable crown shape.

Will hostas grow around tree roots?

The hosta is able to grow near the roots of most trees. Under some trees, hostas grow better than under others, but in general, it is possible. If you follow my recommendations, you may be successful.

Most trees have a shallow root system, and almost all of their roots are 14-16 inches (35-40 cm) deep. However, the roots of some trees are less aggressive and other plants can be grown under them.

All maple species, and especially silver maple, have very fibrous and dense roots. Therefore, I do not recommend planting hostas under these trees.

Red and Japanese maples may be an exception. You can successfully grow hostas under these trees for many years without harming them.

However, if the maple is mature and of considerable size, hostas may not grow well under it. You can dig a hole and trim the roots of the maple and then plant the hostas there. The hostas will grow quite well for a few years. After a while, you need to do it again.

Oak and conifers are the trees under which you can successfully grow hostas. Under these conditions, hostas will need special care, which we will talk about later.

Remember a simple rule: the younger the tree, the easier it will be to grow plants under it.

Planting hostas under trees

hosta under tree

Elegans Hosta under large tree.

Step back at least 1 foot (30 cm) from the trunk for young trees and at least 3 feet for larger trees. Then start digging, using a good quality, sharp shovel.

According to scientific research, many trees can withstand 10% root system damage without serious consequences.

Dig a hole twice the size of the root ball. Use a sharp knife or scissors to cut all of the tree’s roots. Do not touch roots more than an inch thick.

For planting, it is better to choose hostas with a strong rhizome. As a result, the plant will be able to quickly take up free space and compete with the roots of the tree.

In these conditions, the hosta can be successfully grown for many years until the tree becomes very large.

Here’s a little trick that can make life easier for hostas under the tree. Use a shovel every year to trim the tree roots around the hosta.

Simply stick the shovel several times around the hosta at least 1-2 feet from the petioles. In doing so, be careful not to damage the roots of the hosta.

How close to a tree can I plant hostas?

You can plant a hosta no closer than 1 foot to the trunk of a tree. This applies to young trees. For large and old trees, plant at least 3 feet away from the trunk.

Examine the ground around the tree and choose a spot where there are minimal roots. Try not to touch the large roots that provide stability to the tree.

Choose only vigor varieties

The next recommendation is to plant only vigorous, fast-growing varieties under trees. This will allow the hostas to take up a lot of space in the ground and make it difficult for the tree to compete with them.

Large and medium varieties are best suited for this:

  • Sum and Substance
  • Frances Williams
  • Blue Cadet
  • Cross Regal
  • Green Fountain
  • Elegance

Varieties that grow slowly are unlikely to survive long in the shade of large trees. I do not recommend planting the following hostas in such conditions:

  • Mouse Trap
  • Francee
  • Cherish
  • Sagae
  • Fortunei
  • Blue Mouse Ears

Also, do not place next to trees varieties that have most of their leaves variegated, that is, have little green pigment. Such plants are rather weak and will not survive the pressure of tree roots.

Dwarf and miniature varieties are also best not placed under trees because they do not have enough vigor to compete with a large tree.

Water hostas properly

Proper watering is one of the keys to successfully growing a hosta under trees.

The fact is that the trees form a canopy and rainwater gets to the ground beneath the tree in less quantity. Add to that the fact that the tree sucks a lot of water out of the soil, and you end up with dry shade.

Hostas do not like dry soil, so you will have to give them plenty of water. In the first few months after planting, check the moisture of the soil, and as soon as it is half an inch dry, water immediately.

The amount of water will be more than you would normally water a hosta because some of this water is taken up by the tree. Large varieties may require four or more gallons of water per watering. For medium-sized hostas, three gallons is sufficient.

The frequency of watering will vary. Sometimes you have to water every two days if the weather is too dry.

You should also keep in mind that even if it has rained a little, you still need to water the plants because the branches and leaves of the tree will not allow all the water to fall on the ground beneath it. As a result, the ground will remain dry.

That being said, the best solution is to install a drip line. If you do this, you won’t have to waste any time.

A drip line can also be equipped with a controller and a rain sensor.

Mulch your hostas

The next step is mulching. Mulch should be placed around the hosta to retain as much water in the soil as possible. This will also reduce the frequency of watering.

It is best to use organic matter for mulching. If possible, use compost. In this case, in addition to moist soil, you will get extra nutrition for your plants.

Here are a few words about compost. Choose only quality compost from reputable manufacturers. Do not use material from unknown suppliers, as improperly prepared compost can contain aggressive substances that will harm your hostas.

Another good mulching material is pine bark. It also keeps moisture in the soil and lasts longer than compost. However, the nutritional value of such a mulch is minimal.

Spread a layer of mulch 1-2 inches thick. A thicker layer will prevent air from reaching the soil surface, and a thinner layer will not retain moisture well.

The mulch should be around each shrub and cover an area slightly larger than the size of the hosta.

Do not put mulch on the stems. There should be at least an inch gap between the base of the stems and the mulch.