Yoshino Flowering Cherries in bloom on the University of Washington campus - 4/5/09To Do In April:
Mulch garden beds with compost or manure .
Feed plants with organic, all-purpose fertilizers. Apply alfalfa meal to heavy-bloomers such as roses and dahlias.
Treat for slugs with iron phosphate products such as Sluggo.
Pull or treat weeds before they flower and go to seed. This will save you hours of work in the weeks and months ahead if you do a thorough job now.
Make sure that hoses, sprinklers, etc. are in good working order in case of an early dry spell in our weather.
Pay special attention to water containers and new plantings in the event of an early dry spell.
Begin to prune boxwood and other broadleaf evergreen hedging plants as needed. For spring bloomers such as Choisya ternata or Viburnum tinus, prune immediately after flowering.
Prune roses if you haven't done so already. New buds and shoots will be reddish in color.
Inspect perennials and roses for aphids and treat as necessary with insecticidal soap (not detergent soap) or other nontoxic solution. Be advised that pyrethrin-based insecticides are known to burn new growth on some plants and many stronger insecticides can kill off the aphids' natural predators (ie. ladybugs).
Shop at local nurseries for peak selection of trees and shrubs, especially hard-to-find items.
Only plant the hardiest of spring annuals and vegetebles until mid-May when evening temperatures are consistently above 45 degrees F.
Hardy spring annuals would include bacopa, lobelia, marigolds, pansies, petunias, snapdragons, dusty miller, etc.. Wait another month for zonal geraniums, coleus, impatiens, begonias, etc..
Hardy spring vegetables would include carrots, celery, lettuce, green onions, mustard greens, Swiss chard, broccoli transplants, parsley and most herbs. Wait to plant tomatoes and basil.
Tomatoes and basil should not be planted out in the garden until the evening lows are above 50 degrees F. Due to high demand you may need to buy them prematurely. If you do, you'll need to keep them outside during the day and then move them into the garage or a greenhouse at night to protect them. You may plant them when it is safe to do so in the days ahead.
Take time to get out and enjoy the beauty of spring. Take a stroll trough the Quad at the UW (see photo above), a trip to a public garden or just a walk around the neighborhood. We could all use some fresh air, Vitamin D and a few flowers to lift our spirits after all the nasty winter weather and gloomy economic news. Spring is here and summer is coming.
Cheers, Tim
