Trees turn color in fall

Fall tree color blog

Fall is a great time of the year. The trees start turning colors and everything looks so beautiful, even the green conifer trees. Evergreen trees should maintain their green color all of the time, right? This time of the year I get many calls on a natural process of evergreen trees called Natural Needle Drop.

Natural Needle Drop

Natural Needle Drop

White Pine with Natural Needle Drop

Evergreen trees turning yellow in the fall may not be a problem, in fact it may be completely natural. Evergreen trees do hold onto their needles, but eventually the older needles are shed from the tree in the fall. When this happens, those needles turn yellow before they fall from the tree. As long as the needles that turn yellow are all on the interior of the tree, there is no real concern. The older needles are the needles that are shed, which will be held on the interior of the tree, not on the ends of the branches.

Natural needle drop is very noticeable on white pine trees because they are naturally not a dense tree and they lose their needles every 2 years, making it quite common. Ponderosa pines lose their needles every 3 years, while Austrian pines lose their needles every 4 years. It is not as common to notice the needle drop on these trees due to the infrequency as well as the density of the tree. Spruce trees will also lose their needles, but much less often. Spruce trees will typically hold onto the majority of their needles for up to 10 years

Deciduous Conifers

It is important to know what you tree is supposed to do in the fall and winter months. We have a couple of trees that are classified as ‘Deciduous Conifers’ meaning that they are a conifer due to their needles and how they are arranged but are deciduous because they lose those needles annually. Two deciduous conifers are commonly found in Nebraska, the Larch and Baldcypress. These trees will lose all of their needles in the fall after first turning brown throughout the entire tree. If you don’t know what type of tree you have in your yard or are not familiar with the growth habit of these trees, you might think they died, when they are really just going through their normal lifecycle.

Fall Color for Deciduous Trees

20181023_152033Speaking of deciduous trees, this is the time of the year when our deciduous trees, those with leaves rather than needles, will change color and the leaves will fall from the tree. As the nights gets cooler and the days get shorter, the tree produces a membrane between the branches and the leaves which causes the leaves to be shed from the tree. Prior to leaf drop, this membrane also causes cessation of chlorophyll from the leaves for the year. At this time, the other pigments are allowed to show up in the leaves.

The brightest fall colors are produced when dry, sunny days are followed by cool, dry nights. The dry, sunny days are needed to break-down the chlorophyll in the leaves allowing the other pigments to be dominant in the leaves. The cool, dry nights are also necessary for fall color because trees need to avoid freezing temperatures which can injure or kill the leaves causing them to stop producing much sugar at all. The sugar content is what increases the amount of the anthocyanin, or red pigment.

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Pumpkins, Spiders, and Mums

Halloween Pumpkins

Now that October is here, we begin to get prepared for Halloween, a day which I personally enjoy. Pumpkins, spiders, and fall flowers are all part of this festival. So, I won’t miss the chance to help you with your holiday decorations and traditions.

Pumpkins

2017-10-28 19.10.50Pumpkins can be used for so many things including carving, decoration, pies, and many other food products. If planted later in the summer growing season, your pumpkins should just be maturing, or have matured within the last couple of weeks. If you are unsure, pumpkins are mature when the rind is hard and can resist penetration from a fingernail.

Pumpkins do need to be harvested prior to a hard frost. They can be ok out on the vine for a light frost, but a hard frost will damage the pumpkin and can damage storage potential and more likely cause the pumpkins to rot. They should be cut off the vine. Do not cut the vine too close to the pumpkin, this can also cause the pumpkin to decay sooner.

If you didn’t grow the pumpkin yourself, check over the pumpkins you are purchasing. Look for good rind with no puncture wounds. Ensure that the pumpkin has a bit of stem attached to the top and choose the correct pumpkin for the use you have in mind for it. Pie pumpkins are best for baking while jack-o-lantern types will be better for carving and for decorations.

Spiders

Wolf Spider, UNL ENTO

Wolf Spider photo by Jim Kalisch, UNL Entomology

Spiders always come to mind at Halloween as a decoration and because they become a problem inside our homes with the cool fall weather. The most common spider that people bring into my office to be identified is the wolf spider. These are one of the largest species of spiders that we will find in Nebraska. They are quite hairy and often times will have 2 white or lighter brown colored stripes down the back of the spider. There are some wolf spiders that can be the size of a half dollar or more, legs and all. These spiders are not poisonous, but they can bite. Most often, a wolf spider will not bite us, but if they do the reaction is usually similar to a large mosquito bite.

Spiders are actually beneficial, but not often desired. They feed on other insects and pests that can move into our homes. The best way to control a spider population indoors is through habitat modification, meaning to seal up all cracks and crevices in your home foundation and around windows and doors to ensure that the spiders don’t move into your home. You can also use the indoor/outdoor barrier sprays to spray around the foundation of your home and around the windows and doors to reduce spider populations inside your home. Also, sticky traps are a great way to manage spider populations indoors. 

Mums

orange mum, pixabay

Mums are not the scary holiday tradition that spiders and pumpkins are, but they are a common decoration for the fall, including Halloween. Garden mums grow up to 18 inches tall and 30 inches wide and grow into a clump. The flowers are 2-3 inches across and can be found in many colors including white, yellow, orange, pink, purple, coral, and deep burgundy red depending on the variety. Mums need to be pinched back in the early summer to help keep the plants to a compact and uniform size and shape and to help flowering. Pinching should be done 2-3 times in June. It should begin when the plants are 5-6 inches high and it should be discontinued around the 4th of July.

Many gardeners struggle with maintaining their mum plants over the winter due to repeated freezing and thawing cycles through the growing season as well as wet, heavy soil or lack or snow cover. Longevity of the plants can be enhanced by planting them in a location that is more protected from north winds, discontinuing fertilization by the end of July to reduce new growth at the end of the season, adding several inches of mulch to the soil around the plants through the winter months, and cutting the plants back in the spring rather than in the fall.