Thoughtful planning, careful plant selection and proper site preparation are essential to the success of new plants in the garden. In spring, searching for new shrubs can be exciting yet overwhelming. With so much new stock at the nursery, it can be difficult to decide what to buy. To be sure your investment in new shrubs pays off, take the time to prepare the site, condition the soil and nurture them. Doing so will benefit the plants for years to come.
Before you plant your new shrubs, find out the pH level of your soil. Soil test kits are readily available at most greenhouse and nurseries. With some exceptions, most plants will thrive when the pH level is somewhere between 5.8 and 6.5. It’s difficult for plants to get the nutrients they need if the level is too high or too low. To adjust a pH level which is too high, meaning the soil is alkaline, add aluminum sulfate. If the soil is acidic and the pH level too low adding lime will create more favorable planting conditions.
Soil composition is also important to plant growth. Most plants will not do well in exceedingly sandy soil or in poorly drained clay soil. Before planting, prepare the site to ensure adequate drainage. If your soil is poorly drained, build up the planting beds by about 6 inches. While wetland shrubs, such as summersweet, can tolerate some standing water, most shrubs cannot. Adding composted bark or other course textured organic material to the existing clay will help improve drainage. Be sure the finish grade of your garden slopes away from the planting beds and avoid low spots as water may not drain for several days.
When planting a single shrub in poorly drained or compacted soil, set it about 2” to 4” higher than its original planting depth and build the soil up to the base of its trunk. This will allow oxygen to reach the roots and cause excess water to drain away from the plant rather than collecting beneath it. The top of the root ball may dry out quickly in the summer, so be prepared to water frequently during hot weather.
Because they are so well drained, sandy soils don’t hold water or nutrients well. Sandy soils, as opposed to clay soils, require the addition of water retentive organic matter such as manure, compost and peat moss. When adding your soil amendments avoid uncomposted bark or wood chips as they tend to rob plants of nitrogen. Use well composted organic products with a rich, earthy smell and a crumbly, dark brown appearance.
Once the soil is properly conditioned and you’re ready to plant, follow these general guidelines. Dig a hole at least twice, but preferably 3 to 5 times, the diameter of the root ball and just as deep. Digging any deeper and setting the shrub on disturbed soil can result settling. The wider the hole the easier it will be for new roots to grow and spread. If the shrub comes balled in burlap then just remove the nylon twine from around the trunk of the shrub. There's no need to remove the burlap completely; removing it can sometimes cause the soil to fall from the roots. If it’s tied around the truck simply untie it and tuck in down along the side of the root ball. Make sure the burlap is real, fake burlap doesn't decompose and will need to be removed or at least pulled away from the rootball.
Container grown plants are installed just as the balled and burlaped are. Before removing the plant from the container check the bottom of the container; roots often will begin growing out of the drainage holes, if they are cut them. If the plant has become root bound loosen the roots before planting.
Next, place the plant in the hole making sure that the top of the root ball meets the existing grade of the garden. Never plant new or transplanted shrubs too low in the ground as it’s a major cause of premature plant decline. Backfill around the rootball with a mix of existing soil, peat moss and compost. Be sure to break apart any clumps of soil since they can cause troublesome air pockets beneath the surface. At about halfway, tamp the soil down lightly, water and let the soil settle. Finish backfilling, construct a saucer around the trunk of the tree and water again. Staking may be needed if the plant is tall and exposed to wind.
Apply 2 to 3 inches of bark mulch over the planted area. Mulching helps to reduce weed growth, retain moisture in the soil and will eventually break down adding organic material to the soil.
Planting shrubs in the spring gives them an entire growing season establish themselves in the garden. While it’s a great time of year to plant, you’ll need to nurture them through the summer months. Hot dry weather can stress newly planted shrubs so monitor them and irrigate as needed. In general, shrubs are very low maintenance and with proper site preparation they can last a lifetime.