Did you know that there are more than thirty species of Linden Trees in the world, but just four are suited to the Denver climate? These Lindens are a popular choice for Colorado landscaping due to their ability to withstand sub zero temperatures and alkaline soil conditions.
Learn all about how to care for fruit trees such as Linden Trees so that they can thrive in your landscape. A happy Linden is a strong Linden, and if your tree is resistant to pests and disease, then you won’t need to use pesticides to treat your Lindens. You will be able to reap the benefits because it’s not just the fruits of these trees that are edible! The leaves, flowers, seeds, and sap are all edible and many of them even have medicinal properties. They are truly impressive trees.
What Types of Linden Trees Thrive In Denver?
Not all varieties of Lindens suit the front-range climate. The American (sometimes called Basswood), Littleleaf, Redmond, and Greenspire are the four species of Lindens that flourish in Denver’s alkaline soil and urban conditions. To better know how to care for these fruit trees, learn how to identify each:
Also called the Basswood, the American Linden is sought after as a shade and statement tree. Easily recognizable with its unique flowers and large, heart-shaped leaves, this Linden species grows to 60 to 80 feet tall with a spread of one-half to two-thirds the height at a medium rate. When young, it has a pyramid shape that grows fuller and rounder with maturity.
The American Linden’s fragrant flowers are attractive to bees, making Linden Trees a potential source of delicious honey. Interestingly, the dark green, coarse leaves are edible and are often fed to livestock.
A major benefit of this species is that it is highly adaptable. It can tolerate clay and a wide soil pH range. The American Linden grows best in full sun and well-drained soil.
This attractive Linden species produces vibrant yellow flowers that hang down on a long stalk attached to a leaf-like wing. Littleleaf Lindens bloom in late summer after most flowering trees have lost their blooms, and their nectar attracts bees and hummingbirds.
The Littleleaf Linden grows in an oval shape at a medium rate and will stand 50–60′ and a spread of around 40 feet at maturity. It grows best in full sun or partial shade, and can flourish in acidic, alkaline, moist, rich, sandy, well-drained, wet, and clay soils. Another benefit of this species is that it transplants well.
Like many of the Linden varieties, the Redmond Linden also produces signature flowers starting in the spring and lasting until late summer. “Redmond” flowers are yellowish clusters that attract bees and butterflies. Taller than other Denver Lindens, the Redmond easily stands 75 feet at full maturity in a handsome full, pyramid shape. Its uniquely large leaves can grow up to 8 inches long.
The Redmond Linden grows well in full sun and is somewhat drought resistant. It prefers moist, fertile soils and can thrive in warmer temperatures, unlike other Linden species. The Redmond makes an impressive lawn tree and is sought after by homeowners since it is resistant to most pests and diseases.
Looking for an attractive shade tree? The Greenspire is your best bet! This Linden species holds a tidy spire-like shape with dark green foliage throughout its lifetime. It shows off in the summer with beautiful yellow flowers and in autumn with a bold show of gold leaves.
Growing at a medium rate in full sunlight, the Greenspire Linden stands about 50 feet tall at maturity. It is ideal for homeowners looking for a low maintenance Linden variety because it is adaptable to both dry and moist locations, and is not preferential to soil type or pH.
Are Lindens Susceptible to Denver Pests?
When it comes to how to care for fruit trees such as Linden, one of the major factors involved is warding off pests. Every tree species has its weaknesses and the Linden Tree is no exception. These are the top pests known to attack Denver Linden trees:
- Galls are structures that resemble growths on a tree’s branches or leaves.
- They form as a response from the tree to the silva of small insects (mainly mites) that feed on the trees in which the plant increases the number of its leaf cells that then grow over and encapsulate the mites.
- Specifically, Spindle Gall forms in response to Eriophyid Mites and are commonly seen on Lindens in Colorado.
- No real harm is caused to the Linden trees from this condition and treatment is not necessary.
The Japanese Beetle
- These pests prey on over 300 species of plants and trees but they are particularly fond of Lindens.
- Japanese Beetle adults chew flower blossoms and leaves, giving them a skeletonized look.
- Japanese Beetles have a one year life cycle, emerging in full force from late June through early August. However, some adults may be found well into September.
- They do not kill Linden trees, just render severe damage to their heart-shaped foliage.
- Japanese Beetle traps are ineffective for the Denver front range zone where the pests are well established.
- The most effective control measure is insecticide. It is important to select an insecticide that is not harmful to bees and other pollinators that benefit from Linden blossoms.
The Linden Aphid
- Aphids are tiny insects that secrete sap from Linden trees.
- If left unattended, they can seriously damage or even kill the tree. But with early detection, aphids can be controlled.
- Aphids are active during mild weather, usually in the spring.
- The pests leave a sticky honeydew residue on the leaves and bark of trees.
- If you see aphid eggs or residue hose down your plants to remove them.
- Insecticides can be used to control large aphid populations, but can also harm natural predators such as lacewings or lady beetles.
The Linden Borer
- This pest is part of the long horned beetle family.
- The American Linden is this beetle’s primary target.
- The borer tunnels underneath the bark and cuts off the flow of nutrients and water from roots and leaves.
- The borer can cause extensive damage and even death to trees.
- The pests are most active during the summer months from June through August and they overwinter within the wood of the tree to emerge the following spring.
- Bulges in the bark, reduced leaf size and a thinning tree canopy are early signs of an infestation.
- The Linden borer causes broken limbs, trunks, and dieback damage.
- The most effective control methods include: trunk injections, sprays and insecticides applied to soil in spring and early summer.
How to Care For Your Linden Trees
If you are planning to add to your landscape and plant a new Linden tree there are special care steps to consider. Properly caring for newly planted trees during the first couple of years is critical to their development and ability to grow and prosper.
Caring For Newly Planted Linden Trees
Success begins with following planting best practices. To plant your tree correctly, follow these suggestions from the Colorado State Forest Service:
- Plant the top of the root ball slightly above ground level. The root collar (flare) must be visible one inch above final grade.
- Set the root ball on solid ground and not on loose backfill in the hole; this will eliminate settling.
- Remove at least the top 1/2 of all wire and baskets from balled and burlapped trees and completely remove containers from containerized stock.
- Adding peat moss or manure to soil in the planting hole is not necessary. (Too much can cause a “potted tree” effect and restrict root growth.) Backfill hole with original soil.
- Do not fertilize at planting time.
- Optimum planting periods are from March 15 to June 15 and from September 1 to October 15.
Once planted, your next priority is tree watering. Newly planted Linden trees are thirsty! They require more watering than established trees and are more susceptible to injury from drought, so it’s best to keep actively monitoring them and stick to a consistent watering routine.
Here are some pro tips for watering your newly planted tree:
- Water deeply and slowly. Apply water so it moistens the critical root zone from near the trunk of the tree to the dripline to a depth of twelve inches.
- Try to maintain consistent soil moisture for better root water absorption.
- Water a newly planted tree every 3-5 days during the growing season. Newly planted trees need water during dry periods in the winter months as well.
What is the best way to water a new tree? Methods for watering include a deep root fork or needle, soaker hose or soft spray wand. It’s best to apply water to many locations under the dripline. If you’re using a deep root fork or needle, insert the device no deeper than eight inches into the soil.
Caring For Established Linden Trees
Well established Linden trees may seem like they can take care of themselves, but to fend off disease and pests they need regular care to be in peak health. Watering and fertilization are the best ways to care for your established Linden trees.
Fertilization for Established Linden Trees
The role of fertilizer is to act as a supplement, or vitamin, to trees and shrubs. Fertilizer is composed of minerals and nutrients that supply the ingredients required for successful photosynthesis and healthy growth. It plays an important role in balancing the Denver soil for Lindens.
This is especially important if you would like your tree to fruit or flower. Fertilizer is important in fruit tree care because it takes a lot of energy to grow anything other than leaves and branches. Even just growing leaves and branches requires a lot of energy. Your trees are hungry!
Fertilizer is not a magic pill for trees that can cure all problems or diseases. Restoring an unhealthy Linden tree that is poorly planted or neglected for long stretches of time won’t be done with a cocktail of fertilizer. But when used strategically and correctly, fertilizer can help developing trees flourish, growing strong and healthy with care and attention.
Our skilled arborists can assess your Linden, test the soil, and check the growth rate, to determine an appropriate custom fertilizer package just for you.
Watering Established Linden Trees
The four Linden varieties that thrive in Denver are all susceptible to drought. Many people believe that drought is only a concern during the hot summer months, but that is actually incorrect. Trees can experience drought in winter too and watering during a plant’s dormant season is just as beneficial.
Root development occurs during dormancy and steady winter watering helps prevent dehydration and premature death in Linden trees. Although trees are dormant, they aren’t just sleeping all winter long. Linden trees are growing their root systems and they require added moisture to stay alive and thrive.
Precise Care for Edible Lindens
With the right care and maintenance, these trees produce growth that can be utilized in all kinds of ways.
The leaves of a Linden tree are said to taste like lettuce and have antioxidant properties. Generally, the younger leaves are more desirable because they have a softer texture.
Linden flowers are often made into tea but can also be eaten raw. Linden tea is commonly used for anxiety, sleep, colds, cough, and sore throats.
Not only are the flowers edible, but the honey that is made from these flowers is highly sought after. Beekeepers time the removal of the honey around when the Lindens are in bloom. The flowers are so attractive to the bees that they head straight for them. The result is a very flavorful honey.
Believe it or not, ground Linden seeds are said to be a convincing chocolate substitute.
The sap from the tree is edible and low in sugar. That said, the low sugar content means you need more sap to make anything close to a syrup. Therefore Linden syrup is not very common.
The fruit of the linden tree doesn’t really have any flavor so it’s not a very desirable fruit. They are also relatively hard and small.
If you need extra help in how to care for fruit trees such as Linden, schedule a consultation and team up with our certified arborists to create a custom care plan.