Gardening Notes For April

Ater a very long cold March, let’s hope April brings some warmer days! It is at least starting off a bit warmer. The colder weather has certainly delayed bloom times for shrubs and seeding times for vegetables. On the positive side, it allows more time for writing and reading our garden logs and completing indoor tasks such as sorting seeds. As the warmth arrives, take a deep breath and prioritize what must be completed vs. what could be postponed for a day or two or to next year. Remember, gardening is our hobby and we do not need any more pressures or deadlines!
Things to do:
• Finish pruning roses, small trees, and cut back shrubs early in the month. The stems of red and golden-stemmed dogwoods (Cornus sanguinea cultivars) and willows (Salix) can be entirely cut back to 12”, or remove ⅓ to ½ of the older stems. Shrub Roses can be cut in half to keep them from becoming overgrown. In early to mid April, Hydrangea arborescens cultivars can be cut back to 3”; Hydrangea paniculata cultivars can either be cut back to 12” or have most of last year’s growth removed depending upon the density of the panicle - those with a large amount of sterile flowers should not be cut back heavily while those with less sterile florets can be cut back to 12” if desired; Hydrangea macrophylla should have the oldest and most branched stems cut to the ground; and Hydrangea quercifolia should simple be shaped. By mid-April, it will be too late to renewal prune Hollies or Yews.
• Finish cutting back ornamental grasses and perennials.
• If you overwintered bananas outside (such as Musa basjoo), remove the insulating leaves and the surrounding wire cage.
• Divide grasses and perennials if necessary. Remember that the center portion of the plant is the oldest and least vigorous and should be discarded. The outer more vigorous ring will yield at least 10 new plants, with 9 of those going to friends, a new garden, or a curbside sale!
• As soon as the early blooming bulbs (Snowdrops, Winter Aconites, Snowflakes, Scilla) have finished blooming, the clumps can be dug, divided and moved about the garden. These bulbs are much more successfully spread about in spring while still actively growing than as purchased dormant bulbs in autumn.
• Continue potting up Cannas, Alocasia, Colocasia and other tropical plants that were overwintered in the basement.
• Edge bedlines and compost the pieces of turf that have been removed.
• Finish thatching and raking lawns. If crabgrass was a problem during 2014, apply a pre-emergent crabgrass control to established lawns before or during Forsythia bloom,.
• Apply corn meal gluten to flower beds as a weed pre-emergent and a mild fertilizer.
• For the Vegetable Garden, finish sowing tomato, pepper, and eggplant seeds. Earlier seeded Lettuce, Swiss chard, broccoli and cabbage seedlings can now be transplanted outside.
• Resist the urge to turn over or work the soil of your vegetable garden if the soil is too moist. In fact, try not to even walk on the soil if possible. If you can make baseballs from the soil, it needs a few more days to drain.
• Early April for those in the South, later for those more North, seed can be sown directly in the garden for peas, beets, carrots, spinach, cilantro, lettuce, arugula, mustard greens, bok choy, peas and turnips.
• Apply fertilizer and lime to lawns and Vegetable Gardens as prescribed by soil test results.
• Remove the wintergreens from containers and plant bulbs, pansies, primroses, evergreen grasses, etc for early spring color. At Rutgers Gardens, we often use Acorus gramineus ‘Ogon’ as a cool, chartreuse accent plant for spring containers!