|1) How frequently does soil require amendments? Do we need to aerate it every year? We are new to gardening and owning a home, and see that our backyard has wood chips (mulch?) on the surface. Do they need to be removed or replaced on a regular basis?
2) Our roses have many many bugs on the leaves as well as dark spots. After some searching looks like we have an aphid problem as well as the black spot disease. What should we do to keep our backyard free from harmful pests?
3) In general what will be the best way to keep pests away from vegetable gardens?
|Soil fertility depends a lot upon soil type and soil condition. In general, you can amend your planting beds with organic matter every year and eventually end up with good garden loam. It's relatively easy: in the spring, dig the planting beds (flower and vegetable) and rake to remove weeds and plant debris. Then spread 4-5" of organic matter (compost, aged manure, leaf mold, etc.) over the surface and dig it in 8-10". Rake the area smooth and plant your flowers or crops. After planting, spread a 2-3" layer of organic matter over the bare soil. This will help suppress weeds and moderate soil temperatures and slow evaporation. At the end of the season, dig the organic matter into the soil. The following spring, after removing the weeds and planting, spread 2-3" of organic matter over the bare soil. Dig this in at the end of the season. After a few years you'll have wonderfully rich soil in which to plant.
Aerating a lawn is typically done every 3-4 years. It takes that long for the soil to compact and aerating helps loosen it again.
Wood chips degrade after 4-5 years. Replacing isn't necessary, but adding new barks when the old layer becomes thin is a good idea.
Roses are high maintenance landscape shrubs. They are prone to fungal diseases and aphids. Making sure the roses get all day sunshine, keeping water off the foliage and regularly pruning will help them stay healthy. Black spot can be prevented to a degree, but not completely eradicated. There are special sprays for roses that address the myriad of problems roses can develop.
As for pests in the vegetable garden, some plants are more prone to problems than others and there are specific controls for each type of pest. You can help your entire landscape remain healthy if you plant a diversity of flowering plants to attract natural predators. (Wasps, bees, spiders, ladybugs, etc.)
Best wishes with your new landscape!