3 common gardening mistakes and how to avoid them

Gardening can be a tough gig, especially for amateurs working on their first garden. Here's a guide to some common gardening mistakes, and how to avoid making them:

Some common garden varieties may become all too common in the garden if you aren't careful, warns Denver botany professor Greg McArthur.

• Although garden centres may try to sell you on easy-to-grow plants (knowing that a fast-growing plant makes for a happy customer), some plants spread aggressively and can be very hard to get rid of once they are introduced in a garden.
• These include ground covers such as periwinkle (Vinca minor); flowering plants like fleabane and other asters, broom, forget-me-nots, hollyhocks, verbena, yarrow and daisies; and other plants such as ferns, mints and strawberries.
• Moreover, some of these plants may leap the garden fence (or, more likely, send roots underneath it) and invade your neighbours' plots or nearby open space. Such invasive species can seriously alter the local plant environment. Most of these plants have their place in a garden, but make sure to keep them reined in by pulling up shoots wherever you don't want them, or by planting such varieties only in defined areas such as pots, containers, beds bounded by pavement or raised beds.

Beware of the self-appointed xeriscaping expert who says all you need to do is plant the right varieties and then throw away the hose.

• To get a proper start on life in your garden, drought-tolerant plants need regular watering for the first year after you plant them.
• After that, as long as you've planted varieties suitable for your zone, these plants should be able to live on the local rainfall in all but exceptional drought conditions.

Seed companies make those boxes or bags of premixed wildflower seeds seem like the answer to all your prayers. Just scatter them on the ground, add water and a beautiful meadow full of wildflowers will magically appear. Be careful -- that's not always the case.

• According to Susan Aldrich-Markham of the Oregon State University extension service, those mixes may contain invasive species that are inappropriate for your area. Some plants that are considered desirable, decorative varieties in one part of North America may turn into harmful weeds elsewhere, in places with different growing conditions.
• One researcher planted the seeds from 19 wildflower mix packets, and all 19 contained species that were invasive somewhere in North America. Eight plants were considered noxious weeds in at least one US state or Canadian province.
• How do you make sure your wildflower garden is safe and appropriate for your area? The best method is to select packets of seeds for individual wildflowers, rather than mixes, so you can choose your own blend and be sure what you're planting. If you opt for a seed mix, Aldrich-Markham recommends buying from a local company, because the more widely a mix is distributed, the more likely it is to hold inappropriate seeds for a given area.
• Make sure the packet lists all of the varieties of seeds it contains, and look up any plants that are unfamiliar. It's a bit more work, but you're better off doing the legwork in advance than planting a meadow from hell.

Especially for first-time gardeners, mistakes are inevitable. Hopefully these tips will let you avoid three of the most common mistakes gardeners make. Good luck!