By Scott Canning, Director of Horticulture and Special Projects
The days are growing rapidly longer. We add two-and-a-quarter minutes a day of “sun up” time every day in March, and when we change our clocks on Sunday March 10th, the change is that much more noticeable. Gardeners start itching to get outside and work, and that’s a great idea….but. It’s good to remember that we have lots of cold, possibly snowy and wet, weather ahead. And this March at the Santa Fe Botanical Garden, we have genuinely muddy, wet soils. It is very important not to walk on wet soils. And especially don’t turn or “work” wet soils. In late winter, soils are at their most vulnerable: They are sticky and full of beneficial air spaces from the winter’s freeze-and-thaw cycle, and will be compacted, irreversibly, by any pressure from footsteps or “work” when wet. Let soil dry to a crumbly texture before engaging in garden activity. This is common and good advice in areas of the country used to “mud season”, but these conditions are not common here, so this warning bears repeating this snowy, wet early spring.
Garden pruning should continue in March. Again, choose your time to be “on the soil” (if you must be) carefully; using a wooden pallet or piece of plywood or even a ladder can help spread your weight, if the mud doesn’t dry quickly enough.
This is the month I prefer to finish pruning any ornamental grasses that I left standing over the winter, which is most of them. I prefer a rather severe haircut, so that I don’t leave much of a collar of brown stubble from the previous years’ growth. Don’t be tempted (yet) to divide big old clumps with dead centers; they recover better if you give a haircut now, but wait until they begin active growth to lift and divide.
Fruit tree pruning, like all pruning, is an art and a science. There are good reference books to help (a favorite among professional gardeners is The Pruning of Trees, Shrubs and Conifers by George E. Brown), but there is nothing like a hands-on course. I highly recommend the course the SFBG offers, “Pruning Young Fruit Trees”, taught by the immensely knowledgeable Tracy Neal on March 2nd—or stay tuned for next year. I offer my yearly class on “Pruning Roses” on April 3rd.
Get a bunch of compost for the garden. If you have room to store some, buy in bulk for a better deal. The compost can be spread when the beds are cut back and cleaned of debris, but wait to work the soil or “turn in” the compost until the soil dries. You can get a head-start by spreading now and turning-in later.
Annual fertilizing can be accomplished this month by using the technique of applying a ring of fertilizer around the root-zone or drip-line, and waiting to turn it in. I prefer organic fertilizers because they feed the soil and its myriad organisms, not just the plant, as liquid fertilizers primarily do. One caveat if you spread now and turn later: Many organic fertilizers use blood meal, bone meal and feather meal as constituents, and some dogs will find these things lying around the garden irresistible. They shouldn’t harm your dog seriously, but a dog of mine got a very upset stomach after following me around and eating lots of ‘PlantTone’!
As you plan for the coming season, please consider adding more native plants to your garden. Insects of all types are in decline and in need of our help, pollinators especially. I’m not a “native-plant fascist”, but I am definitely leaning that way, more so each year.
Keep up with seed starting and grooming your seedlings (I included a link to Margaret Roach’s “A Way to Garden” blog last month for a wealth of sage seed-starting advice and week-by-week calculators). Grooming?? I sometimes use a fan for a few minutes a day to gently flex the stems of seedlings; safer still is gently brushing your seedlings back and forth with a ruler. This mechanical action toughens and shortens the stems of seedlings and helps keep them from stretching excessively, but this should be done in addition to adequate light, which is most critical for compact, healthy seedlings. You can also gently shake the pots or flats of small seedling as you check on their water and general development, which should be done at least once a day.
And most exciting for those sick of root vegetables is that IF your soil is ready, you can start a few short rows of cold-hardy vegetables, like arugula, spinach, kale and most of the mustard-family veggies, which are numerous, at the end of the month. And it’s time for peas soon, but NOT beans- they need warm soils!