Doing the right things now, in winterizing your urban garden, can save you many headaches next year.Preventative maintenance is well worth the effort.
1. Clean Up Your Garden. Fungus, and mildew problems will overwinter in most winter climates, even very cold ones. The fungus and mildew which usually looks like white powdery coating on leaves , starts to show up by August and through the Fall. In the spring, the plants, bushes may look healthy, but the damage is “hiding” ready to reappear. To avoid this year’s problems again next year, it is essential to get rid of all the damaged leaves. Rake your mildewed leaves up completely, and put them into garbage or compost bags. Do NOT put them in your compost ! Compost will overwinter the mildew and fungus spores until next year. If you put damaged leaves in the compost, and then use the compost in your garden next ear, you will spread the mildew to the rest of the garden. Also any leaves left on the ground will overwinter the spores, which will start to multiply all over again in the Spring. Cut down perennials that grow from the ground in spring, except ornamental grasses, allowing stems to poke up through the snow. Annuals roots can be left in the ground to decompose over winter and nourish the soil.
2. Water Your Trees and Shrubs. If you do nothing else, at least do this. Watering your trees and shrubs, including cedars and junipers, should continue right up to freeze up time. This will usually be right up to the end of October, but may be as late as early December, to encourage the roots to grow. The roots are not actually dormant, and still actively grow all winter. Watering should be weekly, depending on weather. A long slow, deep watering is way better than a quick once over. Small amounts each day is not good as this encourages shallow rooting, making the tree susceptible to future drought and frost damage. On the other hand over-watering can cause the roots to rot. A moisture meter gadget is handy to tell how wet the soil is, so you don’t go too far over or under. Sandy soil will require more frequent watering than clay, as the water drains through it faster. Heavy clay soils can get waterlogged .
3. Protect Your Young Trees from Critters. Young trees just planted this year will require special attention this autumn, to overwinter successfully, that is, to survive and be healthy next year. Deciduous trees will need winter wrap material (the white plastic spiral kind is good)around their trunks to discourage rabbits, raccoons, deer and other critters that love to lunch on the tender bark. Winter wrapping should be continued a few years until the tree trunk is thick enough to not need winter support against wind.
4. Protect Young Trees From Strong Winds. Planting trees in protected areas is best as it will minimize damage from strong winds. But this is not always possible. When your young tree is trying to get established, it needs some help with fighting those cold winter winds. Pound a T-bar metal stake into the ground beside the young tree facing the tree, but with its “back” toward the strongest winds, usually NW of the tree stem.. . If the area is very windy, you may even need 2 stakes opposite each other, or 3 stakes arranged in a triangle. Be observant about your wind patterns and learn from them what your trees and shrubs will need in protection. Evergreen shrubs (cedars, junipers, and the like) will need burlap covering the first year or so, to protect from winds, and sunburn, especially the Southwest. Do not bind too tightly: leave some air to circulate. Once they have toughened up a few years , wean them off the burlap, and just use wind string round and round starting at the bottom and up to the top. Plastic netting is also good to protect from freezing rain.
5. Mulch, Mulch, Mulch . Your garden surface needs protection around small and large shrubs, trees and large perennials to lessen the freeze/thaw cycle damage. Mulch is like an insulating blanket. Using bark mulch, usually cedar or pine, several inches all over the garden ground is very effective. Only use leaves, crunched up , if they are free of disease, mildew and fungus. Pine needles are good for acid loving plants, like rhododendrons. Snow, especially the fluffy kind, is one of the best insulators for tree and shrub roots. But you may or may not get enough or the right kind. When snow builds up enough to be useful,you can heap it up at the base of your trees and shrubs to insulate the roots.
Now sit back and enjoy your winter garden !
Keep an eye out for more upcoming articles on urban gardening by this author.