Trees look great in a garden and look even better with plants and flowers growing underneath This creates the understory of a tree.  Small trees such as holly and dogwood are understory specialists.

Many different types of small insects and animals live in the understory layer. The understory is dark and humid because only a small amount of sunlight makes it to this layer.

As the tree grows its branches and roots expand which means the area underneath can become barren. The tree roots quickly soak up all available water and the tree canopy spreads out blocking the sunlight so only a few plants can grow there.

When planting under a tree, follow these tips to help establish your plants and flowers.

First and Foremost - Protect the Tree.

Take care when digging around a tree. It is easy to damage the roots and bark at the base of a tree.
Damaged bark can cause disease to infect the tree.
Use a trowel rather than a shovel as some trees have shallow roots. If you find a root, leave it and go to the next spot.

You don’t want to compromise the tree.

Start Small

Choose shallow rooted herbaceous perennials, bulbs, and groundcovers which are best suited to sharing soil space with existing tree roots. Plants like crocuses, snowdrops, hardy cyclamen and are good choices. They may require a lot of watering at the beginning but as they grow, they will adapt to their surroundings. Watering the lower trunk near the root collar can lead to fungal problems so aim sprinklers or irrigation nozzles away. If needed, add a little amount of soil blended with some organic matter for your plants but no more than a couple of inches as you don’t want to starve the roots of the tree.

How to Plant

Don’t be symmetrical when planting by planting in rings around the tree. You want your planting to look as natural as possible.

Choosing Plants

Choose a couple of key plants and then plant them in large swaths. Choose ground cover plants like lily of the valley, ferns and hardy wild ginger to mix with the crocuses, snowdrops and bluebells etc. Perennials are better than annuals as there is less disturbance to the tree.

It helps if you choose plants that can handle some drought. You will still need to give your plants attention for their first year, no matter what you plant. But it will be easier if you choose plants that are more resilient.

And choose some plants whose leaves look good all year round, like hostas and heucheras and ferns.