What To Do With Japanese Maple In September – Essential Tips For a Sensational Fall Display
Five steps for healthy, beautiful trees
September is the time to prep Japanese maple for the colder months ahead. With the hot and sun baked days behind us, these plants need to recover their energy reserves quickly before heading into their dormant period.
Known for their spectacular fall color and intricately cut foliage, Japanese maple trees are a standout feature in gardens of every shape and size. Grown as bonsai trees, and as sculptural centerpieces in a border or planter, these deciduous, slow-growing trees have exquisite lines and a delicate charm that instantly elevate any outside space.
With shallow root systems and tender leaves, these versatile plants are susceptible to changeable temperatures and weather, so they do require a degree of care. This month essential tasks include judicious pruning, irrigation monitoring and prepping for cold weather (for which these large zip-up shrub protectors from Lowe's are very handy).
Prune Lightly To Maintain Shape
September is a poignant moment in the gardening year, when perennials, trees and shrubs have established, put on new growth and are settling in for the dormant period. Having nurtured them to this point, now is the time to nip Japanese maples into shape.
'Japanese maples are relatively problem free and require a very light hand in creating a graceful figure. The majority of the pruning done to maintain a graceful shape is done after the spring growth has hardened off. This period of time is the end of July into the beginning of October,' explains Daniel Schachner, horticulturist working in the Japanese Garden, Seiwa-En, at the Missouri Botanical Garden.
'During this period, any distracting or structurally problematic new growth can be controlled. The most important pruning tip is to prevent branches that will overlap or rub. A light hand is best.' Daniel also adds.
'If you have questions on pruning or are looking for a professional, the Aesthetic Pruner Association (APA) trains and certifies professionals on this type of pruning.'
A sharp, clean pair of Pro Bypass Secateurs such as these from Amazon, will make this job a joy. Plus if you love a dramatic and sculptural tree, be sure to consider Coral Bark Japanese Maple from Garden Goods Direct with it's contrasting red bark and lime foliage.
Protect From Fast Cooling Temperatures
Japanese maples often need protection in winter. Ice and snow particularly take their toll, with frozen soil preventing roots from absorbing essential nutrients and rot from setting in. The sheer weight of snow can also cause fragile branches to snap and stems to split, causing irreparable damage.
Knowing how to protect plants from frost, and taking action before cold, stormy weather arrives is a smart move, but options vary depending on the size of the tree plus where and how it is planted.
'If growing a Japanese maple in a pot in a climate that experiences freezing temperatures, it would be best to bury the pot in mulch to protect the root ball from freezing or they may be overwintered in an unheated garage,' he continues. Other preventative measures include lifting the plant off frozen ground using heavy duty rubber pot feet or a smart rolling plant caddy, both from Amazon.
For in-ground trees, winter tree care options can be limited. Frost cloths whether made from burlap, spun polysterene or breathable polypropylene fiber, all from Lowe's, can all be useful.
'Cold protection is tricky. If the tree is exposed to the wild in the winter and is small, you could do a wrapping in burlap during dormancy,' says Daniel. 'This is a difficult task, as the trees get larger and it usually is not feasible. Right plant, right place.'
Choosing a Japanese maple cultivar that suited to your climate is all important. Varieties with red leaves tend to cope with more sun in cooler climates, while those with green foliage prefer a shadier spot. 'Acer palmatum 'Emperor One' has also shown promise in cold tolerance in lower hardiness zones,' says Daniel. Find this Japanese maple variety at Lowe's.
Keep A Watch On Watering
Now is the ideal time to review your watering routine, whether you are nurturing an established Japanese maple or newly planted tree. Whether you are growing Japanese maple in a pot or planted in-ground , deep watering is invaluable and maybe not as often as you think.
'When it comes to watering, trees–in general–prefer a long, deep watering period on less frequent intervals,' says Daniel. 'Setting a sprinkler or irrigation system to run for a long period of time but only once a week or every other week is a safe choice.'
It is worth monitoring how much water is being distributed during each session, with Daniel's ideal being 2 to 4 inches. 'Testing your sprinkler system for the rate of application will help apply water properly. An irrigation audit is possible by setting out a container within the irrigated zone that can capture water to be measured.
'Most turf irrigation systems will water for a short period of time, but multiple applications per day. This can be problematic as the soil cannot properly drain moisture, and it encourages fungal pathogens in the root system. It is important to observe the soil around the tree; irrigation should only be applied if the soil is draining properly.'
If you don't wish to install an irrigation system, there are other watering solutions to try. We like the look of the Dew Right Tree Watering Donut from Garden Goods Direct or the Element Kink-Free Soaker Hose from Lowe's.
Time To Plant New Trees
September marks a short window for planting Japanese maples in the ground. With cooling air temperatures, a mellowing sun and still-warm soil, conditions are perfect for a tree's root system to settle before wintry weather kicks in.
'If you are planting a maple in the ground, early spring and mid-fall, typically in September and early October are the best times,' says Daniel. 'However, if planting a small tree, it can be done any time in the growing season with success if water is applied properly.'
Soil preparation for good drainage, is all important, and can vary depending on soil type. Loosen clay by mixing in topsoil, well aged compost or pine bark or bolster sandy soil's water retention with well rotted compost. Also, be sure to break up heavily compacted soil. This sturdy garden digging fork or Spear Head Spade, both Amazon, will easily handle the task.
Plant the tree so the graft line is above the surface and in a hole that is slightly shallower than the tree's root ball. This will discourage water from pooling around the main stem and to drain efficiently.
Top Up Mulch
This month, prior to leaf fall, is the perfect time to top up a tree's mulch layer. 'Mulch keeps soil temperature lower and helps retain moisture. When applied to an appropriate depth, it develops a fungal mat that helps to suppress weeds and break down the mulch for nutrient use in the tree,' explains Daniel.
While a mulch depth of around 4 in( 20cm) is ideal, a shallower depth will still aid plant growth and limit weed growth.
'It is important when applying mulch to any tree that the mulch must not be touching the trunk and bark of the tree. Any area above the basal flare, where the roots meet the trunk, does not handle the persistent moisture that the mulch retains and can lead to the death of the cambial layer and therefore the tree,' Daniel adds.
Organic mulch options can include homemade compost, grass clippings or fallen leaves but bought-in products such as Cleanstraw Pine Needles from Trees.comand Pine Bark Mulch Nuggets from Target will create a professional and polished finish.
Daniel is a experienced horticulturist working in the Japanese Garden, Seiwa-En, at the Missouri Botanical Garden
What To Shop
One of the best trees for fall color, Japanese maples are just the start of a cool season garden filled with impact. Take a look at these native alternatives trees to expand your collection, and snap up some of these plants for pots in September for winter color.
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