1 If you haven’t done so yet this spring, fertilize your lawns immediately. Use a fertilizer with a high “first number” – like 23-14-10 or 33-24-10 for example — instead of the 10-10-10 we usually recommend as an all-around fertilizer. The first number tells you how much nitrogen is in the fertilizer, and this is what grasses will benefit from most, especially when their leaves are set to grow full tilt.
2 Last call to spread lime too, if you didn’t do so in the fall, when we told you to! Use granular — not powdered — limestone, for a slow and steady release of this important soil additive. While you’re at it, be sure to sprinkle some limestone around your “neutral” and “sweet-soil-loving” plants, like roses, pink hydrangeas (but not the blue ones) and, especially lilacs.
3 Fertilize all your prized trees and shrubs. Use 10-10-10 here as your all-around fertilizer. Be sure to fertilize your vegetable beds, your flower beds and all your spring bulbs with 10-10-10 too, to keep everything blooming beautifully, year after year, and to help your bulbs expand their numbers for next year.
4 Apply fertilizer that’s meant for evergreens to them: As opposed to those plants that like “sweet” or “neutral soil,” all your evergreens – including azaleas, rhododendrons and hollies – need fertilizer that’s high in acid and in sulfur and copper compounds, in order to “green up” and do well. (And your blue hydrangeas need acid fertilizers to exhibit really blue flowers. Use lime, and they’ll be purplish or even pink – especially if that’s what they were bred for.)
5 Keep your grass well-mowed, but not too short: Longer blades will totally shade out dandelions and other weeds – without chemicals – if you give your lawn good fertilizer, and regular but not too-short haircuts.
6 Keep your flowering trees and shrubs in good shape by trimming them back a bit, removing crossing and/or overcrowded branches and using the flowering cuttings indoors: Unless you live in an English-style mansion house, or an Italian-Renaissance-style palazzo, please, please don’t shear your flowering shrubs into tight cones and balls. Try instead to maintain the shapes that nature intended them to have, which will also help them to bloom more beautifully.
7 This is a great time to edge your beds. Use a sharp spade to define their space and neaten them up.
8 Hold off on mulching…please…while you can pull out or scratch out any and all emerging weeds with ease, and until the ground warms up: If you feel you must mulch, be sure to keep the mulch at least eight inches away from the trunks of your trees and shrubs. Too much mulch, spread too close, will make the trunks susceptible to insects, damaging molds, sun-scald – and to out-and out rotting. Remember too that mulch extracts nutrients from the soil while it decomposes.
9 Not mulching for a while will also let you plant many flower seeds directly into the ground now – like sweet alyssum, larkspur, cosmos, marigolds, zinnias and many other flowering plants that actually benefit from direct seeding – and from having the small seedlings transplanted by you.
10 Plant, plant, plant: Now is the best time to plant almost everything.