Gardens are alive with blooms and new growth this month

May is a month of remarkable growth and flowering in the garden. The collections at the Chicago Botanic Garden seem to change on a weekly basis as plants grow and come into flower.

It is a busy planting season for many gardeners and using good planting techniques will ensure success in your gardens.

Early in the month be careful when installing plants such as tomatoes, impatiens and petunias that prefer warm weather and will be damaged by a late frost.

The average date for the last frost at the Garden is May 15.

Keep a focus and use good basic garden maintenance practices such as mowing grass high will result in a stronger lawn that will better resist weeds and more stressful growing conditions that come later in the year with hot and dry weather.

Attention to the basics can make gardening easier and more successful.

LawnsUse a mulching mower that leaves the grass clippings on the lawn. This means less work for you and it recycles those extra nutrients back to your lawn. Regardless of which mower you choose, you need to mow more frequently during spring due to rapid grass growth. Mulching mowers, in particular, do not work well in tall, wet grass. Rake out wet clumps to dry evenly on the lawn. Keep the blades on your mower sharpened for a better cut. Sharpen them after every eight hours of use.Mow grass at 21/2 to 3 inches high, and frequently enough so that not more than one-third of the total height is cut each time. Most lawns are cut too short. Maintaining lawns at a taller height promotes strong roots and helps choke out weeds. In hot weather, short lawns can burn quickly and weeds are more likely to move in.General garden careMany garden beds have irregular edges. Beds will look better and be easier to mow along if they have smooth flowing curves. Use a pliable garden hose or rope to lay out your new bed line. All clumps of grass should be removed from the bed and any clods of soil should be broken up and spread around. Mulching is always a good garden practice but avoid the "volcano effect" around trees caused by piling soil and mulch up around the trunk.A flat, sharp spade has many uses in the garden. Since new spades do not come sharpened, use an electric hand grinder to put a bevel on the inside edge of the spade. A well-sharpened spade can cut through thick sod and make your work in the garden much easier. An all-metal spade is great for digging out stumps and other heavy work; a lightweight fiberglass or wood handled spade works well for maintenance and planting.Take photographs of your bulb displays now and make notes as to where new bulbs can be added in fall to improve the display. Observe your garden over the course of spring and early summer and make a 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 about the garden.It's a beneficial garden practice to deadhead (manually pinch off spent flowers) rhododendrons and azaleas after they finish flowering. This is also the correct time to prune their branches to reduce size, if necessary. You can increase the flower count for the following year by very carefully pinching off one-half of the sticky new green growth emerging from the spot where the flowers once were.If your soil is too alkaline, elemental or granulated sulfur can be added to lower the pH. Rhododendrons and azaleas are examples of plants can benefit from sulfur applications in many gardens in Chicagoland. Apply sulfur to your blue hydrangeas that are turning pink to get the flowers back to blue. The flowers 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, applying one-half of the recommended rate each time. Work the sulfur into the soil and water in. Sulfur is slow-acting. Wear plastic gloves and be careful to keep the dust out of your eyes when applying.Rotate the crops in your vegetable garden to control pest problems. This is the easiest way to practice organic, integrated pest management gardening. Many insects and diseases attack vegetables within the same plant family. By planting vegetables from a different family in a problem area, you minimize a repeat infection. The basic families include the cabbage family (broccoli, cabbage, cauliflower, Brussels sprouts, radishes and turnips); cucumber family (gourds, melons, squashes and cucumbers); nightshade family (eggplant, potatoes, tomatoes and peppers); goosefoot family (spinach and beets); onion family (leeks, garlic and onions); legume family (all peas and beans), and the carrot, celery and parsnip group.PlantingIf you have a lot of digging to do in your garden, it's important to have your utilities located before starting the work. In the suburbs, call J.U.L.I.E. at (800) 892-0123 to have your yard marked for underground utilities (this is a free service). Their website is illinois1call.com. In Chicago, call DIGGER at (312) 744-7000. It generally takes two working days for these services to locate your utility lines, so allow plenty of time before digging. These locating services will not mark any lines you have installed yourself such as a gas line to a grill or wires for landscape lighting. Dig carefully by hand if you are working within 18 inches of either side of any marked underground utilities. Also take care when digging in gardens with underground sprinklers.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. You will need to 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. Plants that have been grown in containers should be moist when planted in your garden. When you remove the plant and its root ball from the container, spread out or cut all the roots that have encircled the root ball. These roots have grown in a circle inside the container and could eventually girdle or choke the plant if not redirected to grow out and away from the plant. This will help the new plant get established in the ground more quickly. Monitor watering needs carefully after planting as the lightweight container soil can dry out quickly and stress the plants. Generally, containerized plants need more frequent, but light watering to get them established.Containers you are going to use for seasonal plantings should have at least one bottom hole for drainage. A layer of gravel in the bottom of the container is not necessary. Fill with a lightweight, fast-draining soilless mix - avoid heavy garden soil. Leave enough space between the top of the growing medium and the pot to make watering easy. Very large containers can be partially filled with wood chips or empty plastic pots to conserve soilless mix. Separate the "filler" from the growing mix with landscape fabric.bull;Tim Johnson is director of horticulture at the Chicago Botanic Garden.False13342000After rhododendrons and azaleas are done blooming, pinch off the dead blooms. It will help the plant put all its energy into the blooms, as opposed to the seeds. False