This year we get to test the rule: Once the birch leaves get to the size of a squirrel's ear, the possibility of a frost is gone for the season. Yeah, I know, I know ... and what about the possibility of another snow in May? Trees may not be able to walk, but they are not dumb. They held off this year because they know when to leaf out, mine just a day or so after the snowfall.
So, there is a very low probability of frosts from here on. However, the soils are still too cold for optimal plant growth. My plan is to harden off plants this week and get them into the ground next week.
Once the leaves on your birch trees are open, it's time to harden off all indoor-grown plants to make sure they acclimate to growing outdoors. All indoor grown plants need time to adjust to the UV rays of the sun that are blocked by glass. This will prevent leaves from burning and turning white. It will also allow plants to adjust to the drying effects of the wind, also not part of the indoor environment. Don't lose your investment; harden off your plants.
You can make hardening off simple, or you can complicate things. The simple way is to take anything you know was grown indoors and place it outdoors on the north side of your house where there is no sun. Leave them there for a week or so, making sure they are properly watered. The last day or two, move them to where there is dappled shade ... just a bit of sun poking through leaves, for example. After this, you are done.
The more complicated way is to leave the plants outside for a few days in deep shade. Then drag them back and forth into the sun for half an hour, an hour the next and two hours on the final day. It is the more traditional and surer way to protect your plants, but I think it is more ceremony than it is worthwhile. There are UV rays in the shade too.
During the hardening off period, water your plants with a diluted solution of organic fertilizer. This will ensure they have every nutrient going into the ground with their soil ball. You will also need to apply endomycorrhizal fungi if you are planting in a new garden or a garden that has had chemical fertilizers in the previous season. There is a soluble form that can be watered in while hardening off or granular types that you dip the plant roots into when transplanting.
Next, rototilling is not in the organic gardener's vocabulary. After a garden has been created, it is not necessary and will, in fact, result in more trouble than you can imagine. The practice kills soil food web organisms, including those that produce most of the carbon needed in soil to grow plants. It destroys soil structure and results in anaerobic soils. If you need to disturb the soil to plant something, make a small hole -- don't destroy the entire garden. I just saved you from a lot of work. Besides, it is probably still just a tad too wet in your gardens to be walking around and planting. Plus, as noted, the soil is too cold.
Finally, it is time to gather soil samples for testing. This is my new rant, in case you haven't noticed. It is something every gardener should do to save money, time and the environment, yet inexplicably, so few of us do so. We all know that information is power. Why not have information that tells us exactly what our soils lack instead of knee-jerk buying and applying fertilizers on an annual basis because some guy with a fake Scottish accent tells us to?
Locally, try the Soil and Plant Analysis Laboratory (533 E. Fireweed Ave.) in Palmer. My favorite outside testing facility is Kinsey's Agricultural Service in Missouri (kinseyag.com) and SoilTest Farm Consultants in Washington (soiltestlab.com). Yes, you have to pay $30 or $40, but you will save that much in the short run and more in the long one.
Jeff Lowenfels' new book, "Teaming With Nutrients," the story of how plants eat and what to feed them, has just been published by Timber Press.
Garden calendar
PLANT SALE AND PUBLIC GARDEN DAY CELEBRATION: MAY 25, FREE ENTRY. ALASKA BOTANICAL GARDEN MEMBERS GET FIRST HOUR AT SALE (GREAT REASON TO JOIN NOW). ALL SORTS OF ACTIVITIES, INCLUDING MY FIRST BOOK SIGNING OF "TEAMING WITH NUTRIENTS: THE ORGANIC GARDENER'S GUIDE TO OPTIMIZING PLANT NUTRITION." MORE INFORMATION AT ALASKABG.ORG.
LAWNS: MOW AND MULCH DEBRIS. LEAVE IN PLACE. WATER AND, IF NEEDED, AERATE. DON'T THATCH OR RAKE. DO NOT FERTILIZE OR LIME. WEED AND FEED PRODUCTS ARE NOT EFFECTIVE UNTIL LAWN TEMPS ARE IN THE HIGH 60S, AND THEY ARE POISONS. READ THE LABEL BEFORE BUYING, AND THEN DON'T BUY. AND WASH YOUR HANDS.
PERENNIAL GARDENS: RETURN MULCH. CHECK AND REPLACE LABELS AND STAKES.
NURSERIES: WHAT ARE YOU WAITING FOR? GO AND BUY PLANTS. YOU CAN'T HARDEN THEM OFF IT YOU DON'T HAVE THEM.
Jeff Lowenfels
Gardening