Seedlings need to be thinned so they each have enough room to grow without competing for light, water and air. Try to spread seed apart at planting, then watch your seedlings for crowding. Transplant as needed or simply remove excess seedlings by cutting them off at the soil line with scissors.
Most deciduous trees are pruned, if needed, in late winter or early spring. Pruning is usually limited to removal of dead or damaged branches and to removing branches that cross and rub against each other. If a job is large enough to require a chain saw, you probably should call a professional arborist.
Growing closely related plants such as tomato, potato, and pepper in the same location each year may encourage a pest or disease buildup in the soil. Try not to plant vegetables from the same group in the same location 2 years in a row. Moving them will help break the pest or disease cycle.
Locate Spring Bulbs
Spring blooming bulbs such as crocus and daffodils are a joy to behold after the long dull winter season. After blooming, these plants produce temporary foliage and then go dormant for the summer; next spring they will grow again. Mark their locations now so that you don't accidentally dig them up next summer.
Too Wet to Dig
Digging, tilling, planting in or walking on wet soil can damage its structure. Clay based soil is especially sensitive to mistreatment -- clods stick to your shovel when it is wet. Test soil moisture by gently compressing a handful, then let go. Workable soil breaks apart, wet soil stays together in a lump.