Spring garden temptations are real, but discipline beats impulse buys

Garden centers are filling up with plants and providing many temptations for us avid gardeners. Take the time to select plants that are suited to your garden’s growing conditions and fulfill your design criteria to ensure a successful garden. Bright, colorful flowers do much to cancel out good judgment when it comes to buying plants. Focus on the discipline of planting the right plant in the right location to yield a better-looking garden that requires less maintenance.

Take photographs of your bulb displays now and throughout the month as they come into flower and make notes as to where new bulbs can be added in fall to improve the display. Some bulbs thin out over time and need occasional replenishing for a consistent year-to-year display. Observe your garden over the course of spring and early summer and plan to add bulbs that bloom at different times to extend color. This will make it much easier when you are ordering and planting bulbs later this year. Remove any rogue bulbs that may have seeded themselves around the garden.

If your soil is too alkaline, elemental or granulated sulfur may be added to lower the soil pH. Rhododendrons and azaleas are examples of plants that can benefit from sulfur applications in many Chicago-area gardens. Apply sulfur to your blue hydrangeas if they are turning pink to return the flowers to blue. Hydrangeas turn pink in more alkaline soils. Add three pounds of sulfur per 100 square feet of garden area per year. It is best to apply in the spring and fall, using one-half of the recommended rate each time. Work the sulfur into the soil and water in. Sulfur is slow acting. Wear protective gloves and be careful to keep the dust out of your eyes when applying.

Many trees are planted too deeply. To determine the proper planting depth for your new tree, locate the trunk flare — the place where the trunk widens at ground level. If the trunk flare is not showing, open the burlap to find the flare. Plant the tree higher in the hole and very carefully remove the excess soil above the roots to expose the flare. Generally, planting 2 to 3 inches higher than ground level is a good idea in heavy clay soils. It is best not to amend the backfill returning to the planting hole, but it is OK to amend the soil at the surface around the tree. If the root ball appears to be loose, remove the wire basket and burlap after the tree is positioned in the planting hole.

• Tim Johnson is director of horticulture at Chicago Botanic Garden, chicagobotanic.org.