The seasons are changing and I’ll be posting consistently about the weather/gardening for the next few months. Its been a great, if hot summer and I don’t know about you but I’m glad for the respite from watering. I get asked a lot of questions at the shop but the one that surprised me over and over was when and how to move a plant. I thought I’d give a few tips on how this may be done successfully. I get the impression that people are carting their plants all over their gardens with very mixed results. Here is how to do it and succeed.
The right tool for the job
Moving a plant can be daunting and if you don’t have the right tool it can be downright arduous. The correct shovel not only ensures success it takes the toll off of your body. My favorite shovel and one that I think all gardeners should own is a ditching shovel. Unlike its clunky common cousin with a wide scoop, this shovel has a long 30″ blade that is just 5″ wide. The wooden shaft is only 3′ long and ends in a plastic or metal ‘D’ handle. The long blade is built for cutting into the ground precisely and will easily cruise right through heavy clay, even gravel, as well as woody roots. I use it for not just ditches and moving plants I use it for planting bulbs or carving a hole in a tight space anywhere you need to be precise. This implement directs you to use your foot to absorb most of the effort and is much easier on your body as a whole. It makes a great gift for a gardener. Its sharp enough to pierce cleanly though perennials that require division and when digging and moving a plant it is indispensable.
The right time for the job
I’ve moved plants myself in every season of the year and I if you do it correctly and follow a few pointers you can mitigate the hazards of heat and dry, cold and wet. The best time to do this is when conditions are as moderate as possible. That is mid-late spring and early to mid autumn. Or when temperatures fail to exceed 80ºF or drop below freezing. I like to move plants on an overcast day when its in the 40’s to 60’s- this is ideal if not practical with people’s schedules and lets be honest most people are active when its hot. So, then pick the most moderate time of the day- early morning or late afternoon/evening to forestall too much shock. I like to dig the new home hole first before I unearth the plant to be moved and this lessens the amount of time the plant spends twisting in the wind. I fill that hole with water while I am unearthing the new tenant. This will wet the soil column on all sides of the new hole and will tease the roots into fresh territory.
Some terminology that will help you along
“How big a rootball should I dig?” Is a query I get time and time again. The answer is that the live material you see above ground is often mimicked with the same amount of subterranean growth. A better way of envisioning this is to understand a plants drip line. That is the extent of its foliage- if you look directly down on a shrub for instance it would be the outer limits of where the shadow is cast or where water drips off the foliage. The drip line gives you a fantastic cue about where to start digging around this line. Another method, which I’ve used and does help is to pre-root prune a woody plant or vine. Simply use your ditching shovel to slice directly down into about 1/3 of the way around the plants root mass- slice gently going down at least 2′. Ideally, this should be done 2-3 weeks prior to moving. Its thought to put the plant into a more conservative mode- slowing growth and conserving energy. It puts the plant on notice. This can be especially important when moving large shrubs. Though prudent it isn’t always practical. So identify the drip line and you will understand how big of a rootball you will need to extricate.
Avoid shock with several different tactics
Use your shovel to cut around the drip line and insert the blade as deeply as possible. This should be done carefully and methodically. Once you have encircled the plant then go back and start to use the blade to insert and gently lift. Distribute the leverage evenly around the plant. What you should not do is to grab the plant and pull. This will only lead to sadness. Keep working the root ball with your blade gently easing it up out of the ground. If you have to slice through large roots then dig even deeper. Almost all plants have horizontal feeder roots that radiate out in a circle just below the soil surface. You want to retain as many roots as possible. Gently roll the plant out of the hole and transport it to the new site. If the plant begins to wilt or if it is out of the ground a while and under stress I highly recommend pruning the top of the plant to equal the root mass. Otherwise hose down the entire plant and make plans to keep it moist until installation. Notice where the plant wilts along the stem. Cut off the wilted foliage. This will leave older hardened foliage that will survive the move more readily. And the plant will not waste energy rehydrating damaged tissue. It should be said that deciduous plants should be moved in dormancy and this is best done in late winter prior to spring growth.
Settling in for a good life.
Dig your new hole about twice as large as the new rootball. This can seem like a lot of digging but it will ensure that your plant has stability and the resources to get up and start growing. Before you insert the new plant remember to fill the hole with water. Then set the new rootball in the water and carefully back fill with soil. This does three important things. It hydrates the plant, it wets the soil column below and alongside the hole directing root growth, and it settles the plant eliminating air pockets and ensuring stability. Don’t be hesitant to stake unsturdy plants- recently planted things tend to wobble and a good windstorm can rock it and tear the roots. Adhere the plant firmly with gardening velcro to a sturdy piece of bamboo or rebar. Then moving out from the trunk make a “moat” around the trunk about 1′ wide with a raised lip. This reservoir should be filled regularly to ensure that the roots grow happily directing the water straight down. To be honest there are very few woody or herbaceous plants that shouldn’t be watered frequently if the weather is hot. Under those circumstances you seriously cannot water too much for the first week. after watering its vital that you mulch with a material that will even out the soil moisture and mitigate temperature swings. Compost or fine bark mulches all work well. If you are planting into a gravel mulch you can replace that when done which will also shade and protect the soil inhibiting moisture loss.
Good to go
Pay careful attention to your recently moved plant. If the season is right you should see new growth in several weeks. If your plant is anemic or yellow you might consider applying fertilizer at the time of the transplant. For broad leaved evergreens I find nothing superior to cotton seed meal (about 6.2.2). Simply dust several handfuls in the moat before you mulch. For perennials I try to give a good handful of all purpose organic fertilizer (about 4.6.3). Its important to note that repeatedly moving young plants will cause so much stress that you could easily lose it to shock. Let plants develop a substantial root system before shifting them all over. If you can only get a small root ball- you should consider cutting off as much of the top growth until you have an equal part roots to photosynthetic material. The larger the rootball, attention to water, and mulch should have your plant established in no time. One last thought. Broad leaved evergreens that are moved from the shade to the sun can easily sunburn. Make plans to shield them from the hot sun with old pieces of screen or remay. The foliage should gradually acclimatize to the new light levels.
Summer 2017 (June, July, August – meteorological summer) was the second hottest recorded at PDX. Records there have been kept since 1940- but even longer local records in context confirm it was an exceptionally hot year. This is surprising considering our hottest summer of all was just two years ago (2015) and 3 of the warmest summers of all time have occurred in this decade. This scorching summer we topped 90º 24 times (average is 12) and we hit 100º three times (average is once at 100.3ºF) with 105ºF the warmest of all- a summit that has only been reached 10 other times in Portland recorded history. We are anticipating a weak La Nina this winter which could mean quite a few things. I’ll wait to comment until new long range forecasts are out. Hopefully, there will be some consistency. Stay tuned.