"For obvious reasons, I spend most of my time emphasizing what you should do in the lawn and garden," says Paul James. "But occasionally, I emphasize what you shouldn't do. After all, gardening, like life, is full of dos and don'ts."
Don't fertilize trees, shrubs or other landscape plants during the late summer, especially if you live in an area where freezes occur suddenly and as early as September or maybe even before. The reason is simple: When you fertilize landscape plants, you encourage new growth and that new growth is extremely susceptible to freeze damage, which may not be apparent until the following spring. Besides, plants have been busy growing for several months, and by late summer they're ready for a rest and to prepare themselves for dormancy.
Do fertilize the lawn, especially in late summer to early fall while the grass is still green. In fact, fall is the best time of all to fertilize the grass. "You see, turf grasses have the ability to store carbohydrates which they are able to produce in large quantities, thanks to fertilizer throughout the winter months," Paul says. "Then, when spring rolls around, they have the nutrients they need to produce a lush green lawn." But avoid products high in nitrogen because that's not the nutrient turf grasses need most during that time of year. Instead, use a balanced fertilizer, meaning one with an NPK ratio of 3-1-2 such as 6-2-4 or 12-4-8.
When it comes to cutting the lawn care, don't scalp it. Even if you're getting ready to re-seed, scalping stresses the turf, and it encourages more weed growth by allowing the sun to reach more soil.
Don't use a pre-emergent herbicide two weeks before or after sowing grass seed. "A pre-emergent herbicide works by preventing seeds from sprouting, so it will prevent the grass seeds from sprouting, too." If you have a lot of weeds in your lawn, use a post-emergent herbicide to zap the weeds without hurting your grass.
Don't stake trees. "I can't understand why people stake trees, especially since research has clearly demonstrated that staking isn't necessary," Paul says. In fact, staking actually results in a weaker tree. The trunks of unstaked trees are allowed to sway or bend in the wind, and that makes stronger trees.
Don't walk in your garden beds, or at least try to limit the amount of walking. Walking compacts the soil, and plants simply can't grow well in compacted soil. Since it's next to impossible to avoid walking in your garden beds, consider using a board to walk on to distribute your weight evenly and reduce compaction.
Don't work the soil while it's wet. "This is one of my all-time favorite don'ts, and it's one I hope you'll remember," Paul says. Working the soil while it's wet destroys its structure, and it may take months or even years before it has a chance to recover. "In the meantime, you're left with a bunch of ugly dirt clods, which are hardly ideal for growing the plants."
Don't overwork the soil. "A lot of people have the mistaken notion that good garden soil has the consistency of a fine powder, so they constantly work the soil with either a tiller or by hand. " Well, good garden soil is nothing like a fine powder at all. Instead, it should have a wide range of particle sizes and fairly coarse textural feel made possible by a high organic matter content." Because soils with a range of particle sizes and lots of organic matter don't compact as easily, they drain a lot faster yet have more water-holding capacity, contain more nutrients and oxygen, and as a bonus, they're easier to dig in.
Late summer is the perfect time to get started fertilizing the lawn, planting cool-season grasses, trees and shrubs, purchasing mums, and ordering your spring flowering bulbs.