June brings better gardening weather, what a welcome change!  Although it’s been dry for Vermont spring, recent rains have created better conditions to get new plants into their outdoor homes for the summer.  Broccoli, cauliflower, cabbage, onions, and salad greens have mostly been planted out.  It’s time for heat loving plants like basil, tomatoes, beans, cucumbers, squash, okra, sweet potatoes, & peppers to be in the ground.  Annual flowers like geraniums, petunias, marigolds, nasturtiums, and snapdragons will do well outside now too.  Early transplanted tomatoes and pepper will do well, but cool nights have slowed growth so be patient, they will soon get going! 

Transplanting into the garden is a major change for plants and taking some care to minimize the stress will help plants get through transplant shock better and increase their growth.  It’s also time to start watching for early insect pests, to prune some flowering shrubs, and NOT to fertilize your lawn now.

Whether you grow your own seedlings (Congratulations!) or buy your garden plants, they will need some preparation for the transition into the “real world” outdoors.  There are big differences between the comfortable indoors (house or greenhouse) and the tough world outside so plants need a little help to adapt to those harder conditions outside.  This process is called “hardening off” and it is easy if you follow a few basic steps. 

Hardening off is a necessary transition for plants because they have to adapt to multiple environmental factors at once.  In addition to getting direct sunlight outside vs through a window or from artificial lights, they also are dealing with new temperature swings (day to night), wind stress (flexing & dehydration), and varying moisture levels.  The best approach is to make sure plants have some time to get used to the different conditions. Think of a winter Vermonter hitting a tropical beach for a whole day in the sun, Not good!

Depending on how you raised the plants indoors, most plants do best with a gradual transition over 10-14 days.  Start by putting them outside on warmer, cloudy days (or in a shady spot) for 2, 4, 6, and then 8 hours per day.  After 4-5 days they can be placed in direct sunlight for about 4 hours per day for a 2-4 days and then full sun all day and left out overnight for a couple days before transplanting.  Keep them moist and protected from strong winds.  Here is a good video on hardening off plants at  https://www.almanac.com/video/how-harden-plants

All this is under optimal circumstances, assuming you have the time.  Few people will actually do the whole transition completely so do what you can.  Remember too, there is little advantage to getting plants out at the earliest possible date, so a delayed transplant is probably better to minimize transplant shock.  Previous articles on “When To Plant” provide some guidelines.

Before transplanting begins get your soil is ready.  That does not mean rototilling or turning of soil is needed, or even desirable, because it is not.  It does mean the soil should be drained and as weed-free as possible.  You’ll never be 100% weed-free so stop trying!  I use a broad fork on raised beds which doesn’t turn the soil upside down (bad idea) but gently loosens it up without destroying important soil structure or releasing nitrogen into the air (a greenhouse gas).  A basic garden fork will also work well, without turning the soil over.  Spring is also a good time to work in some mature compost (not fresh manure) to add organic matter and nutrients.  Compost is “mature” when you can no longer recognize the original ingredients or it’s full of earthworms.  The preferable time of day for transplanting is usually late afternoon (after 4 pm) on a calm day (wind dries your plants just as well as your laundry!) or on very cloudy days to reduce dehydration.

Plants are best transplanted in the ground at the same depth as they were in their containers with the except of tomatoes (they go in deeper).  Generally, no fertilizer should go in the planting hole but I do put in a small amount (1-2 Tbs/plant) of Phosphate (rock or colloidal phosphate, bone meal, bone char, etc.) since this is the one nutrient that does not move down through the soil to the roots when applied on the surface.  Phosphate is slow release and will help young roots grow.  Mixed with equal amounts of Azomite (or Green Sand) for micronutrients and your plants are well fed for a full season of growth.

Once your plants are in the ground, they’ll need plenty of watering immediately and for a week or more afterwards until they become established.  This is a great time to offer them some liquid food in the form of fish emulsion in their water.  It’s organic and will release gradually so the plants can take it in over time.  Also, the fishy smell will repel deer and rabbits if that is a concern.  If we get warm sunny weather some shade during the day would be good too. (Think sunscreen)  I use Agribon-19 row cover held up with wire hoops or ½ inch PVC pipe to allow some air flow but it does block the direct sun on tender leaves until they are growing strongly.  Anchored cardboard propped up over plants during mid-day will also do the trick over small areas.

Transplanting is complete after some protection is provided against hungry critters that love those tender new plants.  I have voles (field mice) that can devour a whole row overnight so I sprinkle generous amounts of MoleMax (Bonide), a castor bean repellent, along the rows and it seems to keep them away, mostly.  Also recommended for deer, rabbits, and voles are products like Shake-Away (mint, rosemary, & cedar), and Plantskydd (blood meal) as repellents that are accepted as legally Organic.  The row cover used for shade also hides plantings from deer and insect pests so provides a double benefit.  Of course, full protection with a combination barrier & electric fence is best, but that will be another topic.

There will usually be a few plant failures, it’s hard to get 100% success with anything, so I like to keep a couple spares on reserve to replace those that don’t survive.  It’s nice to have a full row or bed growing.  Finally, now that the soil is warmed, it is a good time to apply an organic mulch in order to provide weed suppression, moisture retention, and soil building.  Straw is one of the best but lawn clippings will also work.  If you use “mulch hay” be prepared to more weeds from the seeds in hay.

Early pest are appearing.  A couple common pests to watch for now are the familiar slugs & snails that will erupt after June rains.  They can devour the leaves of tender young plants but are easily controlled.  Regular hand picking and beer traps work well and an environmentally friendly compound made of Iron Phosphate (Sluggo, Slug Magic, Slug Bait) is very effective.  It even provides nutrients in the form of Iron and Phosphate while eliminating those pests.

This is also the time when Cucumber beetles (striped & spotted) can damage young squash and cucumber plants.  Hand picking them in the early morning is very effective if done daily.  Diatomaceous Earth, Neem oil spray, and yellow sticky traps also work well.  The first beetles are the parents of all the next generations so reduce future problems by getting them now.

If you have had trouble with leaf miners, flea beetles, or Colorado potato beetles in the past I advise covering susceptible plants like young squash, cucumbers, beets, chard, etc. with light row cover such as Agribon until the plants are mature enough to outgrow any damage.

Finally, a free, new smart phone app has been released that is a great resource to identify and control pests & diseases of fruits (apples, pears, strawberries, etc.).  It even identifies Beneficial insects so you know who the good guys are!  The program is called MyIPM and is available for Android (Play Store) or Apple (Apple Store) phones. 

Why is this not a good time to fertilize your lawn?  Despite pressure from the chemical fertilizer retailers to get you to apply early summer fertilizers, this is not the best time to feed your lawn, if there ever is a time when fertilizing grass is a good idea.  While applying lime to improve the soil pH in the spring/early summer is a good idea, chemical fertilizers create several issues.  Applied now, high Nitrogen fertilizers over stimulate top growth (more mowing!) at the expense of root growth.  Strong roots are essential for nutrient and water uptake all season and the grass will suffer come the warmer, drier days of July and August (requiring watering to stay green). 

Finally, since chemical fertilizers are manufactured from petroleum and natural gas their application is responsible for greenhouse gas contributing to climate change and have become unreasonably expensive.  The solution is simply to let your mulched grass clippings stay on the lawn to recycle nutrients and organic matter, making extra fertilizer unnecessary.  If you add shredded fall leaves to your lawn soil in the autumn it will be even better!

Pruning Shrubs.  The best time to prune flowering shrubs is right after they finish blossoming.  Flowering shrubs often set their blossom buds for next year soon after they drop this season’s flowers so pruning later may remove most of next year’s flowers.  If needed, shrubs to prune as flowers go by include forsythia, lilac, azalea, and rhododendron. 

What experiences have you had with hardening plants?  Do you have your own tricks for transplanting to share?  Please put them in the Comments below.