Denver’s spring has arrived three weeks early and this means plants are blooming ahead of schedule, especially the bulbs we planted last fall. Tulips and daffodils in a lightly mulched bed may be as tall now as they normally would be on April 8th. Bulbs in a sunny south facing bed, especially against a house or wall, may be already be blooming.
Despite our early spring, if your daffodils are in full bloom and temps fall below freezing, those blooms could freeze. You cannot protect those flowers, but if you would like to slow down growth of plants now emerging, you might be able to do just that.
The process begins by testing the soil temperature. If your tulips and daffodils are now breaking through the soil surface, do a test using the meat thermometer from your kitchen. A compost thermometer also works.
Brush away all the mulch around plants and push the point of the thermometer down as far as it will go into the soil. If the reading is below 60 degrees, then you should be able keep the soil cool and slow development of these emerging plants. The process ends by adding more mulch to the bed. Additional mulch shades and insulates the soil to keep it from warming in the sun. Keeping the soil cool will slow down growth of the plants
If the reading is above 60 degrees and plant growth is taking off, you probably can’t slow down the growth because the soil is warm and activating growth. These plants, however, could probably use a splash of water. Give them enough water to hold in the soil 1” below the surface.
Information courtesy Associated Landscape Contractors of Colorado, sponsors of the 9News Water Wise Garden and the 9News Kitchen Garden.