Horse chestnut trees are deciduous, flowering trees indigenous to Greece, Albania and Bulgaria that can reach heights between 90 and 100 feet. Horse chestnut trees produce showy, white, fragrant flowers in spring, followed by large, brown seeds in fall, which are referred to as conkers. Plant horse chestnut trees in full sun and make sure they are provided rich, well-draining soil.
Dig a hole approximately three times the width of the horse chestnut tree's root ball, but approximately its same depth. Make sure your planting location is not near any paved areas, since the root system of horse chestnut trees can be invasive.
Mix one half to 1 cubic feet of peat moss, aged manure or dehydrated compost with the soil you extracted from the planting hole. A soil amendment to regular garden soil can help facilitate drainage, which is especially important if the soil is heavy or clay-like.
Remove the horse chestnut tree from its growing container. Place the container on a sturdy surface and strike downwards with a hammer or a stout block of wood near the drain holes to loosen, then slide the container from the root system. If you are planting a burlapped horse chestnut tree, simply set the horse chestnut tree into the planting hole.
Hold the horse chestnut tree vertical in the planting hole as you scoop in a few shovel fulls of the soil and organic matter mixture to secure the horse chestnut in place. Pour water into the planting hole until it is one-third to one-half full. Scoop in more of the garden soil and organic matter mixture to fill the planting hole one-third full.
Cut the tie that secures the burlap to the stem of the horse chestnut tree, if you are planting a burlapped horse chestnut tree. Peel back the burlap to expose the top half of the root ball. Make sure the top of the root ball will be sitting at the same level in the soil as it is currently growing at.
Scoop in the garden soil and organic matter mixture to fill the planting hole full of soil. Gently tamp the soil down using your hands or feet.
Spread out a 2- to 3-inch layer of grass clippings, pine bark or other like material for mulch around the horse chestnut tree. Keep the mulch 1 1/2 to 2 inches away from the stem of the horse chestnut tree. Water the horse chestnut tree thoroughly using a steady, slow stream of water so it can reach down to the root system.