What to do in the garden in March was the topic of Gene Sumi's latest talk to our Golden Spades group, and as I already reported here, that definitely includes pruning. But there's lots more to do, so keep on reading. Then get out there.
Buy and Plant Vegetable "Starts"
This is the best time to plant vegetables like asparagus crowns, seed potatoes, onion and garlic sets, strawberry plants and rhubarb roots - and buy them asap while the selection is large and they're at their freshest. Seed potatoes should be planted by mid-March - real soon!
And for small spaces, growing potatoes above-ground in barrels works great. No digging is required, and your potatoes won't get speared by mistake at harvest time. Finger potatoes are the best type for this method of growing. By the way, new potatoes should be harvested when the flowers fade - unlike old potatoes, which are harvested later, when the leaves die.
Start Seeds Indoors for Planting in May
Get going on this as soon as possible - especially if you want to grow a variety that isn't available as a transplant (a/k/a "start").
For weed control, apply pre-emergent herbicides
If you'd rather prevent weeds than wait until they emerge to kill them, pre-emergent weed preventers need to be applied in March to be effective. (And Gene likes Portrait in the lawn and either Preen or Amaze in flower beds.) It's important to completely cover the top layer of soil with these granular products, and then water them in well. They will then form a surface barrier that lasts 8 weeks, so time your application right. These products act by preventing cell growth in new plants.
An organic product Gene recommends is corn gluten meal, which works a bit differently and unlike the chemical products mentioned above, it works on both crabgrass and broadleaf weeds. It's also a high-Nitrogen organic fertilizer! It needs to be applied in spring and fall for at least three years to get good results, so be patient. Corn gluten works by preventing root development by the weeds. But remember it works equally well to prevent grass seed from developing roots so again, timing is key!
An important point about organic weed control is that it ultimately is easier but requires some tolerance because, Gene says, "You're never going to get 100% success." 90-95% success is achievable, and that's good enough for most of us.
Apply dormant pesticide sprays
Dormant pesticide sprays are horticultural oils that kill wintering-over insect eggs and fungal spores. They must be applied when the air temperatures are between 40 and 85, and that means the temperature when applied - you don't have to worry about it dipping below 40 later in the day or overnight. Never apply hort oil in the summer, on live green leaves. It works as a temporary application of paraffin and makes leaves look shiny. Insects and their eggs then have no access to air, and are smothered.
Cut Back Ornamental Grasses
Do it now, before there's the danger of cutting off new growth with the old.
Q&A Covers Grubs, Moles, Voles and Vegan Fertilizers
To deal with Japanese and other beetle grubs, apply grub killer at the end of July or the beginning of August. That will wipe out the initial brood of grubs, so that there won't be ANY the next spring. It makes no sense to apply grub-killer twice a year. Moles eat grubs and other insects in the soil so wiping out grubs will help reduce the mole population - though they'll still eat earthworms.
And guess what - the "Juicy Fruit" remedy actually works! Cut the pieces length-wise and drop a couple in each mole hole. They'll eat the gum but won't be able to digest them - so the cause of death is presumably intestinal blockage. put in mole hole. Voles actually do more damage because they burrow deeper, among the roots.
And for organic gardeners who'd rather avoid bloodmeal, a byproduct from slaughterhouses, Gene recommends cottonseed.
Seed potato photo credit.