Good morning gardeners!
Our average last frost in Portland is March 15th and that is just 2 short days away! It is a good date to keep in mind when garden planning and planting. Frost occurs at 32 degrees and most annual vegetables and herbs are not able to survive temperatures that low. Please keep in mind this date is an AVERAGE based on previous years. We could still get an overnight frost. So far the 10 day forecast appears to be frost-free. This is great news for eager gardeners!
This Friday and Sunday saw partly sunny with 60 degree days here in Portland. Talk about spring fever, yikes! Wonderful days for gardening and getting some much needed sunshine on my skin! However, please remember it is not officially spring until March 21st and March weather is wildly unpredictable with rain, hail, wind, and fluctuating temperatures averaging in the 40s/50s.
For optimal planting conditions not only do day temperatures need to rise, the soil needs to warm, and dry out some. In wet cold soil potato tubers will rot, seeds won’t germinate and transplants will struggle to grow. As March proceeds into April we generally have more ideal planting conditions. Think cool season crops, it is way to early for summer heat lovers like tomatoes, cucumbers, squash, basil, etc--you will plant these crops after May 15th.
Working in wet gardens causes soil compaction that impacts plant health. I’ve had my raised beds covered with a frost blanket that is keeping the soil warm and drier through the rainy season. On a dry day at the beginning of March I prepared my raised beds by removing the frost blanket, hoeing the fall-planted crimson clover cover crop, leaving greens on soil, sprinkling on an organic granular fertilizer, adding a fresh layer of compost, and then replacing the frost blankets. By mid-end of March when I assess the weather the raised beds will be prepped and ready for planting.
During the sunny warmer weather on Friday and Sunday I worked on my herb garden-both containers and a raised bed. It is wonderful timing to divide and repot herbs and perennials grown in containers. The cool weather of spring was perfect for planting annual herbs that thrive in the cooler weather like chervil, cilantro, and parsley. As well as hardy perennials like english and lemon thyme varieties. I think that subject warrants an entire separate post that I am working on now!
Cool Season Crops to Plant in March:
Jerusalem Artichokes/Sunchokes-from tubers
Potatoes-from seed potato tubers
Onions-from bulbs or bunches
Direct seed in the garden with protection of a frost blanket, cloche, cold frame or plant transplants directly into the garden
Escarole & Endive
Leeks-transplants are best
Radish-direct seed is best
Turnips-direct seed is best
I would wait a little later in March to see how the weather goes for planting: broccoli, cabbage, cauliflower. Or if you want to plant these now from transplants into the garden be sure to keep a warming frost blanket handy or use some other kind of protection from a cloche, cold frame or low tunnel. I would also hold off until late March into April for direct-seeding beets and carrots. Make sure the soil has warmed up or their seeds won't germinate!
March is a great time to get started with your herb garden. Cool-loving annual herbs like chervil and cilantro should be planted now from seed or transplants. Biennial parsley can be planted now. Additionally perennial herbs like chives, lavender, oregano, rosemary, sage, and thyme can all be planted from transplants in March.
Late winter into early spring is the ideal time to plant small fruit and fruit trees in your garden. This time of year you will also get the best selection at nurseries. Consider planting a dwarf or columnar fruit tree such as apple, Asian pear, pear, cherry, or plum which all grow excellent in Portland. Fruiting shrubs, canes, and vines include:
And don’t forget the strawberries!
Spring is right around the corner. Happy Planting!