Spring planting tips from a gardening meteorologist...

What a difference a couple of weeks makes! We were enjoying an unusually prolonged spring for these parts and riding the fence between burgeoning drought to our east and notable flooding to our west. Summer has definitely caught up with us. The two maps below say it all - our rainfall was less than half of normal and temperatures a whopping six to seven degrees above normal during the two-week span, May 18-31. Even with the storms that hit parts of the area yesterday, this is forcing plants to suck up a lot of our moisture reserves in a hurry.

Percent of normal precipitation (left) and departure from normal temperature (right) for the period May 18-31, 2011. (NOAA)

Now to the main topic: xeriscaping. Sounds like something out of a sci-fi story, where they vegetate a new planet, doesn’t it?

Mayb some of you have heard of xeriscaping, a method of gardening or landscaping that minimizes water needs. For me, it was always something I associated with rocks and cactus in the Arizona desert. Well, taking a course from the USDA a few years ago, I got a real awakening. It’s not just about rock gardens, it can be adapted to any environment and can be every bit as inviting as the grandest English garden.

There are several key features of xeriscaping that help to keep water needs at their lowest possible, and might be useful given the drier pattern we’re in now.

First, compost is essential. This stuff should go down on top of your beds once a year. At least two inches of it will enrich the soil, whether sand or clay. In addition to aiding water retention, compost supplies plenty of nutrients for plants to thrive and improves rooting conditions. There are plenty of nurseries that deliver compost by the truck load, or for smaller city gardens many have it bagged now too. Leafgro is a good one and here is a link to retailers in the area.

Second, mulch on top of the compost helps to keep water-sapping weeds under control. A couple of inches of shredded bark can make weeding a lot less work-intensive and further helps to hold in the moisture.

Third, avoid runoff by keeping slopes terraced or use a ground cover and speaking of plants.

Fourth, use appropriate plants. There are multitudes that work for this area. Nurseries and gardening books and magazines are very good sources for what plants are water misers. I do want to give just a few examples of my favorites and if you have some, please share. For deciduous trees, I love the gingko, holly, oak and magnolia, and for evergreen, I like arborvitae and blue atlas cedar. Good shrubs for low water use include butterfly bush, hydrangeas, mock orange and nandinas. Favorite perennials that handle limited moisture are daylilies, cone flower, phlox, Russian sage and sedums. Herbs include lavender, rosemary and thyme. Even annuals have a place in this landscape with such things as marigolds, lantana, cosmos and coleus.

Good luck keeping things watered and who knows this drier pattern may break later this month with a little luck! Let me know if you have any topics you would like covered. See you in two weeks.

Capital Weather Gang meteorologist David Streit is also an active gardener. He earned a certificate in landscape design from the USDA Graduate School and volunteered many years at the National Arboretum.