It's not uncommon for busy homeowners to leave all the gardening and gardening decisions to the paid gardeners. However, there are two aspects of maintaining a healthy garden that the homeowner really should be supervising. The costs to the homeowner, the potential damage to plants, lawns, pollinators and beneficial insects, and the potential for harm to the environment all can be reduced when gardening practices are monitored.
Here's a quick primer on watering and on the use of pesticides and fertilizers that will, hopefully, encourage homeowners to regularly discuss what's going on in their gardens with their gardeners.
Some homeowners have the gardeners set the irrigation timers themselves. But not all gardeners have the time to make the weekly adjustments as temperatures change that are necessary to conserve water and to save money on the homeowner's water bill. Homeowners should know what type of lawn grass is planted, be aware of irrigation timing and recognize the shade and sun patterns in their own gardens. Sunny areas will require more water than shaded areas.
Well-mulched planting beds with well-amended soil require less water than bare beds with compacted soil that drains poorly; the mulch slows evaporation and the well amended soil holds water longer. Take a walk through your garden and evaluate the watering needs (dry spots, soggy areas) and the soil and sun/shade conditions so that you can work with your gardeners to minimize water usage.
Broad spectrum insecticides do reduce pest insect populations but they also kill beneficial insects as well as pollinators including bees and butterflies. And they have a long-lasting residual effect. If your roses had aphids last week, but you don't see any this week, ask your gardener if he applied an insecticide to kill the aphids and ask what product he applied. If pest insects are a persistent problem in your garden, the cause may well be the use of chemical broad spectrum insecticides.
Pest insect populations actually explode when beneficials have been killed off. Buy lesser toxic insecticidal products such as neem oil and insecticidal soaps that kill only the targeted pest insects and have them handy for the gardeners to use.
Runoff from high-nitrogen fertilizers is infiltrating our drinking water supply. Bermuda lawn grasses need monthly feeding from April through October; fescue and perennial rye lawns need feeding in the spring and fall months when they are actively growing.
All other blooming plants can be fed monthly during their growing season with a low number, lower nitrogen (less than 10%) granular fertilizer that can be stored next to the lesser toxic insecticides. Encourage the gardener to cut down fertilizer amounts. A half a cup of a low number fertilizer applied monthly from February until September is enough to keep your roses healthy and blooming.