Garden Life: Maintenance of planters, lawn vital in late summer

By Robb Rosser, Columbian Gardening columnist


photoRobb Rosser

Just as we need hydration in the hottest days of summer, all container plants need special attention in hot, dry weather. This is especially true at the end of summer after the planters have given us months of color performance. Most important is to assure each container enough water to keep the soil moist to within an inch of ground level. This may mean daily watering if temperatures stay high, especially any planters fully exposed to the elements.

Hanging plants are especially susceptible to drying out since they are exposed on all sides as well as on the bottom. Water flows quickly through a hanging basket and continuously leaches nutrients from the soil. Plant fertilizer needs to be supplied throughout the season for continued growth and flower production. As summer wanes, well-maintained pots and planters can still take us all the way into the next season.

If your garden features annual and perennial flower color, mix a solution of liquid fertilizer into your regular watering schedule every few weeks. Many nurseries keep their demo plants blooming with a light solution of liquid fertilizer with every watering. If the soil in your pots or planters should ever become completely dry, first water the plants well before adding fertilizer. Keep in mind one other key to extended flower performance: regular deadheading of spent flowers encourages another flush of blooms.

Summer lawns get hammered by children playing, guests and visitors walking across the turf areas and the ravages of full summer sun. The upkeep of our lawns requires regular, scheduled watering and mowing. If you choose to have a lawn, how it looks affects the appearance of the rest of the garden. Although there are those who dislike any lawn turf in a contemporary garden, I believe that flowering borders and pathways look their best when framed by lush, green, well-mown grass.

For those of us who water lawns throughout the summer, remember that fewer good soakings that distribute at least an inch of water a week are better for your lawn than lots of quick, shallow sprinkles. By watering deeply you help the grass form a deeper root system. Water early in the morning when there is less wind and evaporation than during the heat of the day.

Lawn-mowing tips

Garden industry recommendations include raising your mower level to at least three inches and cutting the grass often. The longer grass will shade the root system of the entire lawn for better water retention. On the other hand, don't wait too long to mow. You should never have to shorten the grass by more than a third at one mowing. In addition, schedule larger blocks of time for seasonal lawn maintenance tasks such as aerating, dethatching and fertilizing.

The evidence is in that using a mulching mower with a sharp blade has a positive impact on a healthy lawn. Since grass clippings contain 3 to 5 percent nitrogen, they feed the lawn if you let the mulching mower do its job and leave clippings where they fall. Don't bag them. This can also reduce your annual lawn feeding program by at least half. Highly maintained lawns, those mowed low, heavily fertilized, and liberally watered, are the most subject to disease. You can help fight disease by backing off on fertilizer and water and by raising the mowing height by 25 percent.

The upcoming change of seasons from summer to autumn is the perfect time to begin thinking about fall planting and transplanting. The onset of cooler temperatures and the possibility of rain bring ideal conditions for adding hardy perennials, trees, shrubs and vines to your garden. Whether rain comes with the change of seasons or not, keep newly transplanted perennials well watered for the first few weeks. Water deeply to saturate the entire root ball. Deep watering also helps establish good contact between the roots and the surrounding soil.

All plants die eventually. Some will die sooner than others, no matter how well you take care of them. If a plant has performed poorly, try transplanting to a different location this fall. If it's still not happy, give it away or send it to the compost pile. If you are planning a new perennial border for next year's garden, give your design enough space to allow access to mature plants when you need to stake, deadhead, or divide. Create a walkway at the back of a deep border. Lush spring and summer growth will keep it hidden during the growing season while your pathway gives you access to complete all seasonal chores.

Robb Rosser is a WSU-certified master gardener. Reach him at