• Repot houseplants this month, providing them with as much sunlight and fresh air as possible. Check for disease and insects, and give plants a good cleaning under a soft spray of water from the sink or bathtub faucet.
• If you have fluorescent lights, you can start parsley, onion seeds, head lettuce, cauliflower, Brussels sprouts, broccoli, cabbage, most herbs, and cool-season flowers (like pansies and alyssum) now so they will be good-sized by spring planting.
• Start a garden notebook or computer log and vow to use it all year. Write down which perennials bloom together and how long they bloom, and start planning planting schedules for vegetables and annuals.
• After the first mowing, fertilize winter lawns with a high-phosphate fertilizer like superphosphate, triple superphosphate, or a complete fertilizer that is 20 percent phosphorous or more by weight.
• Plant transplants such as artichokes (globe and Jerusalem), asparagus, chard, kohlrabi, lettuce, onion sets, peppers, and tomatoes.
• Finish pruning roses by the middle of the month. Transplant bare-root roses. Fertilize established roses with granular fertilizers about the middle of the month. Remember to water the day before application and the day after.
• Chip all leaves, dead branches, and other plant debris collected during the winter. Apply this as a mulch around trees and shrubs or add to the compost pile.
• Prune peach and nectarine trees heavily, removing 50 to 70 percent of last year’s growth. This encourages shoot growth for next year’s fruit crop.
• Shade exotic greenhouse plants to protect them from the increased sunlight as days become longer.
• Check for tan gypsy-moth egg masses on tree trunks and branches. Scrape or brush off and destroy if possible.
• Select pest-resistant cultivars or species when planning the year’s garden. Choose varieties appropriate to the site.
• Inspect hemlocks for woolly adelgid. Plan to apply dormant horticultural oil in April if you find cottony egg masses at the base of needles.
• To avoid making mistakes when you plant, place the plants, still in their pots, where you intend to plant. Step back and view the whole area before committing the plant to the ground.
• Gazania is a heat- and sun-loving flower; start in February for planting out in May.
• After a long winter inside (usually with less-than-sufficient sunlight), scented geraniums often get leggy. Now is the time to cut them back to encourage shorter, fuller growth.