When to Plant Trees for Best Growth

Understanding when to plant trees is what distinguishes a healthy garden from a sad garden. I learned this early on in my career when I planted some maples late in spring. The trees suffered through the summer heat. Timing, so that roots have several months to establish before the heat comes, is vital.

Planting at the right time allows trees to absorb carbon efficiently. They also support birds and pollinators more readily. I've seen trees take off when planted at the right time. Trees can help you save on energy costs every summer by cooling your home.

If you are a homeowner or a nature enthusiast, this information will take you where you want to go. As an arborist with twenty years of experience, I will outline my key takeaway principles. In this guide, we will break down the easy steps to determine the optimal timing for your site and tree species.

Soil temperature provides a more accurate answer to when to plant trees, than calendar dates. I rely on a simple probe thermometer every day. This measurement depth is at six inches, where roots typically grow. The magic number is 50°F (10°C) for at least seven or ten days before the start date.

Consistent temperatures are crucial, as roots cease growth temporarily when the temperature drops below 45°F (7°C). I learned this from experience after losing seedlings of oaks during the false spring. Temperature checked daily for over a week. Don't plant if cold snaps are expected. Roots need warm temperatures to establish themselves steadily.

Warmer regions, such as coastal areas, tend to reach their optimum temperatures earlier. In cooler regions, wait until late Spring to conduct your readings. Record your readings usually at dawn when the soil is at its coldest. Your county extension office or university may have local soil temperature maps and charts that can help determine an estimated timing.

I've witnessed trees take off in soil temperatures as low as 55°F (13°C). It is actually within this range that sensitive species, like magnolias, should be planted. Be sure also to consider microclimates. For instance, south-facing slopes warm much faster than north-facing slopes. A thermometer is more reliable than the odds of the season.

Choosing the best tree species begins with selecting natives such as oaks or dogwoods. These trees grew up with local birds and pollinators (I see chickadees in native maples, while exotic species had no birds). By choosing locally adapted trees, you create a refuge for beleaguered wildlife in your garden.

Take measurements of your space before making a selection. Small spaces should use compact varieties under 15 feet tall. My ornamental cherry tree began to outgrow its home, creating a problem with the fence. Large properties can accommodate shade trees with 20 feet or more of clearance. A canopy spread at maturity should also be considered, in addition to height.

Climate change has rendered traditional hardiness zones irrelevant. I now recommend trees rated one zone warmer than your site. Try the Arbor Day Foundation's Tree Wizard tool. It incorporates soil type, rainfall, and future climate predictions into the decision-making process.

Drought tolerance is becoming increasingly crucial. I observe this phenomenon in my work, where native redbuds and serviceberries outperform non-native species in terms of drought stress resistance. Their roots are deep enough to access moisture that their shallow-rooted exotic counterparts cannot. When choosing your trees, select ones that can withstand tomorrow's conditions, rather than just today's.

To begin, properly prepare the roots. Soak bare-root trees in water for at least two hours. You want the roots to be moist, not drenched. Please do not expose them to direct sunlight or wind. For optimal results, this should be done at least one hour before planting. Loosen the soil ball gently if the tree is in a pot-bound container.

Excavate the hole properly and make it according to these measurements. Make the hole at least twice the width of the root ball, with a minimum diameter of 20 inches or 50 centimeters. Make the depth match the root flare height, not deeper. Loosen soil at the bottom with a garden fork. Put in stakes for anything over five feet or 1.5 meters in height.

Carefully position the tree. Maintain the root flare exactly at soil grade. Position the best side facing your primary view. Radio out roots. Backfill with the soil/compost mix in layers, lightly firming to remove air pockets, being careful not to pack too tightly.

Use water immediately with two to three gallons or 7.5 to 11 liters. Apply three inches or 7.5 centimeters of deep mulch in a three-foot or one-meter diameter ring. Keep mulch at least three inches away from the trunk of the tree. Loose ties and flexibly adjust stakes. Complete all steps within an hour of starting.

Deciduous trees such as maples and oaks require dormant planting during dormancy from late September to early March. Dormancy is initiated when soil temperatures reach 45°F (7°C) and roots begin to grow. Evergreens such as pines require warmer conditions in which root systems are growing over 50°F (10°C). They should be planted in the spring or fall to mitigate desiccation stress during the winter months.

Coastal areas have a particular timing. Plant after these winter storms have already passed and the soil is 55°F (13°C). I overplanted junipers after a winter storm lingered near coastal areas. Urban heat islands allow for an earlier start, whereas mountainous sections are too late. Ensure you always check your microclimate before planting.

Container trees can be planted at any time of year with some precautions. Twice a day in the hot summer months. Bare-root trees can only survive when grown in a fully dormant state, from November to February. I prioritize bare roots for cost savings but container trees for versatility.

Soil thermometers should never be overlooked. I have saved projects before by waiting to plant until a consistent warm-up returned. Root system establishment is poor at temperatures below the critical threshold. Species should match the average soil temperature of your zone, not just air forecasts, for optimal success.

Different tree types have unique physiological differences that affect their planting schedule. Deciduous trees (e.g., maples) grow roots after leaf abscission using the nutrients they stored. Evergreens (e.g., spruces) retain limited root function all winter, but require warmer soils. Bare-root types usually need full dormancy to avoid shock.

Root behaviors change drastically depending on the season. Deciduous trees expend energy below the ground when dormant, and their roots rapidly expand in system size during active growth to support the foliage. I have observed evergreens growing roots slowly during winter, which puts them at risk for drought when the soil freezes.

Evergreens experience a different kind of winter stress due to their leaves remaining on them throughout the year. The leaves transpire moisture throughout the year, even when the soil is frozen and unable to replenish water loss. The result is dead, brown needles that will not come back. I wrap their trunks with burlap in harsh climates, while deciduous trees become dormant.

Water needs vary greatly by type. Deciduous trees use little water when dormant. Evergreens can give, but require steady moisture all year round, especially in windy winters. If trees are planted in the summer, they all require deep watering, but evergreens will show signs of stress sooner.

The lifetime success of a tree depends on timing of planting and species choice. I've seen properly timed trees for decades, as well as poorly timed trees that barely make it through the season. The decisions you make will determine whether the tree you plant becomes an asset or a liability in your landscape.

Proper planting provides significant long-term benefits. Healthy trees not only purify our air more effectively, but also effectively cool our neighborhoods. They provide wildlife habitat year after year. I've even documented how well-planted trees increase property values dramatically, compared to stressed trees.

Use these guidelines the next time you plant. Measure soil temperatures with a simple probe thermometer. Choose species appropriate for your climate realities. Follow the seasonal windows we discussed. Your diligence will create living legacies for future generations.

Begin MVP preparations for your optimal planting period ahead of time. Review your planting site for approximate frost dates and soil conditions. Choose suitable trees for your space. Then plant with confidence because you've given your trees their best chance for survival. Your successful trees will reward you for years to come!