What to do with those leaves, leaves, leaves.

(This blog was originally published on October 22, 2014.)

The other day I was driving through town and really noticed the changing leaves for the first time this fall.  They are looking particularly colorful this year.  The maple trees varieties like ‘John Pair’, ‘Autumn Splendor’, ‘Table Rock’ and ‘Autumn Blaze’ put on quite a show.  My favorite tree at the Arboretum is the Sugar Maple called ‘Table Rock’.  It has consistent orange-red fall color. 

Table Rock Sugar Maple

These leaves, no matter how beautiful, will eventually fall.  Then we need to decide what to do with them.  Here at the Arboretum we compost them.  Leaf compost makes excellent plant food and humus that can be incorporated into your garden or flower bed.  Leaf compost is high in valuable minerals such as nitrogen, phosphorus, magnesium, calcium and other trace elements.  Analysis shows that leaves from most trees can contain up to twice as many minerals as aged manure. 

American Ash

Why wouldn’t you want to make your own compost from leaves?  Good compost developed from leaves also adds organic matter to the soil.  This organic matter is great for aerating heavy clay soils or increasing water holding in sandy soils.  Take advantage of these free gifts.   

Steps for composting leaves:

  1. Collect leaves. Shred them into small pieces to speed decomposition.  Place leaves on the ground which will make it easier to turn and allow beneficial organisms such as worms to infiltrate the pile. 
  2. Initially, put a layer of leaves down several inches deep on the bare ground.  This helps aerate the entire pile.    
  3. Layer compost pile if possible with alternating green (nitrogen rich) and brown (carbon rich) material.  Green material can be grass clippings, food scraps, algae, tea bags or any nitrogen source.  These green ingredients speed the decomposition of the brown material.  Brown material can be leaves, newspaper, cardboard, sawdust, or straw.  These ingredients are generally slow to decompose and clump together.  They need time and moisture for optimum breakdown.  As a general rule, try to have one-third green and two-thirds brown.  The secret to a healthy compost pile is to maintain a working balance between these two elements.  Too much green makes a smelly, anaerobic mess.  More brown is better than too much green. 
  4. Keep pile moist by either manually watering or allowing rain to infiltrate compost.  Not too moist though.   
  5. Turn the pile every few weeks.  This incorporates and mixes all the elements together while aerating the pile.  If the pile is never turned, oxygen which is an essential component in the process of decomposition will be excluded.  Allow the compost pile to reach an internal temperature of 140-160 degrees to kill weed seeds.  If your compost pile is not reaching these temperatures add more green material.    
  6. In 4 to 6 months (next spring) the composting process will be complete.

If you don’t have need of fresh compost, the Arboretum is willing to take your bagged leaves.  We are again filling our leave house with our leaves but can take more.  Just drop your bags of leaves in the bus parking area at the arboretum.  We will take them back to the leaf house.  The leaf house is a great example of decomposition in action.

Quiet stop in the leaf house

The Best Trees for Fall Color

‘The best time to plant a tree was 20 years ago. The next best time is now.’

– Chinese Proverb

 

For many reasons, fall is my favorite time of the year.  I love the cooler weather and changing landscapes.  This signals the end of another growing season, but there are still a few highlights to come. The beauty of the fall wildflowers like asters and goldenrods makes them stand out in a sea of grass.  The native grasses are at their peak with attractive seed heads and brilliant fall color.  It is also a time when trees begin to change, developing shades of red, orange, yellow, and tan.  I know winter is coming, but the crescendo of our gardens is fun to watch.

Native Blackhaw Viburnum (Viburnum prunifolium)

How do trees develop fall color?

Fall color in trees is a result of a complex process of removing the green pigment, chlorophyll, from the leaves, which allows the other pigments to be seen.  For instance, carotene and xanthophyll (carotenoids) are yellow pigments that are produced all year long with chlorophyll.  With the shorter days and cooler fall temperatures, chlorophyll production is slowed and the green color slowly disappears revealing the yellow pigments that have been there all year long.  Green ash and ginkgo are good examples of trees with nice yellow fall color.

Other trees produce red and purple pigments called anthocyanins, which tend to cover the yellow pigments present in leaves during the fall.  As the fall season progresses, the increased sugar content in these leaves works to intensify these reddish-purple leaves.  American ash, shingle oak and shumard oak are nice trees with red fall color.

In trees with a combination of carotenoid and anthocyanin pigments, an orange fall color develops.  Sugar maples, smoke trees, and sweet gum trees are wonderful examples with orange fall colors.

Some of our trees have no vibrant fall color, but rather the leaves turn to tans and browns. This is caused by tannins in the leaves, which accumulate as the chlorophyll is removed from the leaves.

Fall color can be a little different every year.  Plant genetics, and environmental conditions make subtle changes from year to year fun to watch.  Each year, there is a unique beauty in the landscape that should be savored, enjoyed and not taken for granted.

White oak

My Favorite Trees for Fall Color

Shumard Red Oak (Quercus shumardii)

This oak tree will reach a height of 40-60 ft. with a nice rounded-pyramidal habit.  It is a stately tree that produces a wonderful range of colors from deep red and maroon to dark oranges.  Fall color can be quite variable from year to year depending on environmental conditions.  Other oaks worth trying: shingle oak, white oak and black oak.

Sugar Maple (Acer saccharum)

Sugar Maples and many other maples are the quintessential tree for fall color. In Kansas, sugar maples are relatively slow growing but worth the wait as a mature tree can put on quite a fall display.  They reach an ultimate height of 40-50 feet tall and equal spread.  The bright red, orange and yellow leaves appear in October and last for many weeks.  Try the cultivars, ‘John Pair’, ‘Autumn Splendor’, ‘Table Rock’, ‘Flashfire’, ‘Oregon Trail’ or ‘Legacy’ for the most consistent fall color each year.

Table Rock Sugar Maple

Bald Cypress

This is not usually recognized as a tree with exceptional fall color, but when the fine leaves turn reddish-brown in the fall, it is striking.  We have planted Our specimens near the pond where the “knees” can develop. The pyramidal habit reaching 50-60 feet tall make it a majestic tree for certain situations. It is certainly worth a try.

Bald Cypress fall color

Others worth noting:

  • Viburnum rufidulum
  • Viburnum prunifolium
  • Cotinus ‘Grace’
  • Betula tremuloides ‘Prairie Gold’
  • Sassafras
  • Ginkgo ‘Autumn Gold’
  • Carya cordiformis
  • persimmon

We are already seeing signs of fall here at the Arboretum.  Fall color starts in September and ends in November with peak coloration sometime in October.  Cool night temperatures above freezing, calm winds, and sunny days will make the colors more intense.  So, even though it’s not New England, let’s enjoy the beauty of fall.

Sugar Maple






What to Do with Those Leaves, Leaves, Leaves.

The other day I was driving through town and really noticed the changing leaves for the first time this fall.  They are looking particularly colorful this year.  The Maple tree varieties like ‘John Pair’, ‘Autumn Splendor’, ‘Table Rock’ and Oaks like Red Oak and Shingle Oak put on quite a show.  My favorite tree at the arboretum is the Sugar Maple called ‘Table Rock’.  It has consistent orange-red fall color.

 

Table Rock Maple

Table Rock Maple

 

These leaves, no matter how beautiful, will eventually fall.  Then we need to decide what to do with them.  Here at the arboretum we compost them.  Leaf compost makes excellent plant food and humus that can be incorporated into your garden or flower bed.  Leaf compost is high in valuable minerals such as nitrogen, phosphorus, magnesium, calcium and other trace elements.  Analysis shows that leaves from most trees can contain up to twice as many minerals as aged manure.

 

Gingko biloba

Gingko biloba, ‘Autumn Gold’

 

Why wouldn’t you want to make your own compost from leaves?  Good compost developed from leaves also adds organic matter to the soil.  This organic matter is great for aerating heavy clay soils or increasing water holding in sandy soils.  Take advantage of these free gifts.

Steps for composting leaves:

  1. Collect leaves. Shred them into small pieces to speed decomposition. Place leaves on the ground, which will make it easier to turn them and allow beneficial organisms such as worms to infiltrate the pile.
  2. To start your compost pile, your first layer should be several inches of leaves on the bare ground. This helps aerate the entire pile.
  3. Layer with alternating green (nitrogen rich) and brown (carbon rich) material. Green material can be grass clippings, food scraps, algae, tea bags or any nitrogen source.  These green ingredients speed the decomposition of the brown material.  Brown material can be leaves, newspaper, cardboard, sawdust, or straw.  These ingredients are generally slow to decompose and clump together.  They need time and moisture for optimum breakdown.  As a general rule, try to have one-third green and two-thirds brown.  The secret to a healthy compost pile is to maintain a working balance between these two elements.  Too much green makes a smelly, anaerobic mess.  More brown is better than too much green.
  4. Keep pile moist by either manually watering or allowing rain to infiltrate compost, but don’t go overboard.
  5. Turn the pile every few weeks. This incorporates and mixes all the elements together while aerating the pile.  If the pile is never turned, oxygen, which is an essential component in the process of decomposition, will be excluded.  Allow the compost pile to reach an internal temperature of 140-160 degrees to kill weed seeds.  If your compost pile is not reaching these temperatures, add more green material.
  6. In 4-6 months (next spring) the composting process will be complete.

Leaf House

Leaf house at the Dyck Arboretum of the Plains

 

If you don’t have need of fresh compost, the arboretum is willing to take your bagged leaves.  We are again filling our leaf house with our leaves, but we can take more.  Just drop your bags of leaves in the bus parking area at the arboretum.  We will take them back to the leaf house.  The leaf house is a great example of decomposition in action.