Weeds can grow through rubber mulch, but it depends on if you removed all the weeds in your garden beforehand. Weeds already in the soil can grow even when using rubber mulch. However, that doesn’t mean that your garden will be littered with rubber and weeds, but it does mean that the occasional weed might still pop up. Another way you can increase your weed suppression is by using landscape fabric as a second layer. 

Whether a one-time spray treatment to control mosquitoes is enough depends on multiple factors. Often, you’ll notice a big difference after one application. However, mosquitoes are likely to return if you don't reduce attractive standing water habitats. This usually takes four to eight weeks if it’s still prime mosquito season.

Weed control applications usually cost around $100 each for a standard-size yard, and most professionals charge between $30 and $60 per hour for manual weed removal. Your total is affected most by the size of the weeded area. Some weed service companies offer weed control treatments, selective herbicide spraying, and manual removal and upkeep as part of a package, costing around $600 annually. You might pay less if you hire the same company for other lawn services, like flower bed upkeep, aeration, overseeding, and pesticide application.

Very carefully. You should be cautious when using any of the above methods, as any one of them could lead to you accidentally killing desired grasses and plants. However, there are selective herbicides that can target certain plants over others. Look for a product that only affects the type of weeds you want to eliminate and spares the plants you want to keep.