Ian Robertson, Ltd.

Horticulture Tips

April Tips

• Prune roses after flowering and when cutting off flowers throughout the year.  Flowers are produced on new wood.  Form a spur system cutting back new side growth to 4-5' from main cane.

• Overseed bare areas of turf after loosening the surface (If not done in fall).  Use only VA Tech recommended seed mixtures.  Mulch seeded areas with a 1/4" of compost or clean straw.  Water with ROOTS2 biostimulant soon after germination or use ROOTS Turf Food at ground preparation time.

• Resume mowing as needed.  Do not remove more than 1" of leaf blade at each mowing.  Do not cut shorter than 3".

• Boxwood psyllids can be a common problem.  Look inside cupped terminal leaves in April, when buds are first showing signs of opening, for nymphs and white wax.  If not treated in winter, spray with insecticidal soap in April, as new buds begin to open.

• Look for signs of lace bug beginning in late April and continuing throughout summer.  White stippling will occur on older leaves.  Turn stippled leaves over to find lace bugs and black fecal spots.  If present, treat with horticultural soap and oil sprays.  Be sure to treat undersides of leaves.

• Discula disease can occur in dogwoods in cool, moist weather.  Plants in shade, under-story plantings, and those at higher elevations are most susceptible.  Good cultural care is the best prevention for this disease.  Maintain dogwood health by watering during dry spells.  Mulch to reduce mechanical injury and water stress.  Avoid overhead watering.  Watch for tent caterpillars.  In smaller trees, mechanically remove or spray with Bt.  In larger trees, treatment is not normally needed.

• Prune old growth back to vigorous side shoots on forsythia.  Flowers on last season's wood, so dormant pruning will reduce flowers.  Stake peony plants to keep from flopping over.

March Tips