Are Streetlights Bad For Plants – Is Planting Under Streetlights Okay
By: Mary Ellen Ellis
Plants have evolved to sense and respond to changes indaylight as seasons shift, except those that grow at the equator, of course.Disrupting periods of darkness, such as by growing near streetlights that areon throughout the night, can affect a plant in a number of ways, but most areminimal if the plant is otherwise healthy.
Are Streetlights Bad for Plants?
The simple answer is yes. Deciduous green plants,particularly trees, measure light and detect when days are getting shorter andlonger. This helps them decide when to go dormant in the fall and when to startto come out of dormancy in the spring.
The effect of streetlights on plants and trees can disruptthis important process. In the fall, take notice of trees under street lamps.The leaves right under the light tend to stay green longer than the rest of thetree. This delayed senescence is harmful because the tree is unable to take upthe resources from those leaves before they die. Instead, they simply gostraight from green and living to dead at the first real frost.
Streetlights can also be an issue for flowering plants. Thelength of the day for some flowering plants determines when they begin toproduce buds and bloom. If you have certain flowering plants under astreetlight or security light, they may fail to bloom for this reason.
Planting under Streetlights
So, should you plant anything under a streetlight? Certainly,there are many cities and neighborhoods in which tree-lined streets co-existwith lights. Trees and streetlights are usually fine together if the tree’sother needs are well met, if they get adequate water and good soil with plentyof nutrients.
The harm a streetlight causes to a tree, keeping some leavesgreen too long, can cause small amounts of cumulative harm over time. But thisis minimal and rarely an issue if the tree is healthy. The same can be said ofshrubs. Keep your plants healthy, and place them out of the light if possible.You can also use special shields on lights, if they are your own privatelights, that will allow them to illuminate an area without shining on plants.
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10 Best Trees to Plant Along Your Street and Sidewalk
Steve Nix is a member of the Society of American Foresters and a former forest resources analyst for the state of Alabama.
These are among the 10 best trees that tolerate compacted, infertile soils and the general environment found in cities and along streets and sidewalks. These recommended best curbside trees are also considered to be the most adaptable of all trees to the urban environment and are highly praised by horticulturists.
Messy, brittle trees that can cost property owners significant time and money for clean up are not included in this list. Several of these trees have been chosen "Urban Tree of the Year" as picked by The Society of Municipal Arborists (SMA).
Planting vegetables near trees
(Nova Scotia Canada)
My friendвЂ™s community garden bed is close to trees and the plants seem to wilt very fast. He has peppers and broccoli planted. The broccoli that was taken from this bed had no roots when taken out of the ground, but there was no sign of bugs.
There are 6 other people in the garden and they do not seem to have this problem as of yet. Could it be that he's putting on too much fertilizer or getting it on the plants?
Comments for Planting vegetables near trees
I agree with the trees taking the largest portion of the food and water. While in some cases a particular type of tree may stop or slow the growing of "any thing" under their canopy (I'm thinking of pines here) the majority of the problem comes from the tree thinking that you are having a party every time that you feed or water it and that it is the trees birthday. They are VERY thirsty beasties and will suck an area dry if water and food isnt kept up to the area in question. I hope that this helps a little.
If you've got no other options for planting your veggie garden near pine trees, then let's see if we can help you. Horticultural experts and gardeners have proved it's a challenge, but there are ways and means.
Acidity is the mail culprit, this comes from the pine needles that drop. You wont see plants, even grass growing close to pine trees where there are lots of needles. So don't let them form a big mat that decays away underneath, but gather them up and only use them sparingly in layers in the compost or around acid loving plants such as tomatoes, peppers, spuds, lemons and blueberries. Even then, they don't like it too acicidic. A general rule is to aim for a neutral pH of 7 for most plants, and doing a simple soil test would be a good idea in your situation. You can send soil samples away to be tested or buy a home testing kit from garden or hardward shops.
Adding lime will make the soil more alkaline and is a good long term solution - just follow the instructions on the bag. Wood ash is also good, but do go carefully with all solutions because too much too soon can often harm micro-organisms and limit the ability of plants to take up certain necessary minerals.
If your garden gets enough sun and is beyond the drip line of the branches you should be fine. If the soil is difficult close to the trees, you could use raised gardens and fill with quality soil/compost to get going quickly.
By observation, only you will be able to determine the right choice of plants and amounts of nutrients and water to grow healthy plants by trees, there is no set formula for what to add extra, as all situations are different.
Keep a protective eye on your veggies and a wary eye on the big bullies! If your veggies are slow, leaves yellow, succumb to stress or disease, limp etc, then it's time for a remedy. trim off a pine branch, give more water or use drip irrigation, add more nutrients, mulch, compost, wind break, furrows for drainage. and so on.
My Neighbor’s Lighting
Does this remind you of your home?
Many of us have experienced this scenario: a neighbor installs a new light on their property. It’s an unshielded fixture that casts a bright light that spills onto your property and perhaps even inside your home.
This is known as light trespass and it can cause a lot of agony and frustration. Although IDA doesn’t get involved in neighbor disputes, we have provided this resource that we hope will help you resolve your problem.
If the nuisance lighting is from streetlights, see our Bad Streetlights webpage.
To be fair, your neighbor may not even realize that their unshielded lighting is shining on your property, wasting energy, money and creating a safety hazard.
Many people believe that more and brighter lighting makes us safer, but there is no conclusive evidence suggesting that’s true. In fact, glare from unshielded lights can create harsh shadows where criminals can hide. And bright lighting can even make it easier for criminals to work.
So, how do you talk to your neighbor about this situation?
We suggest taking the following steps to educate your neighbor, and by extension your community, about the value of dark sky friendly lighting.
- Make friends, not enemies. Your neighbors probably don’t even realize their lighting is bothersome.
- Stay positive and don’t argue. Be tactful and understanding about your neighbor’s right to light their property.
- Suggest alternatives to their current fixture. Ask them to move the light, shield it, or add a motion sensor so it’s activated only when needed. Offer to help get this done.
- Be informative. Talking to your neighbor is an great opportunity to be an advocate for good lighting. There are many reasons to use dark sky friendly lighting. Read up on the issues regarding light pollution. IDA also has a number of educational resources that can be useful.
- It’s useful to know the local costs of electricity (cents per KWH) and the local lighting control ordinances. This information is available on most city websites, from your regional utility company and on your utility bill. IDA also has this useful guide to help you find out if there is a lighting ordinance in your town.
- You may also want to compile a list of local businesses or homes in the neighborhood with good quality lighting as an example of effective security measures that are dark sky friendly.
- Having a list of shielded light fixtures to provide as alternatives to your neighbor’s current lighting is also recommended. Use our Fixture Seal of Approval database to find dark sky friendly fixtures and devices.
- Don’t dismiss their need to feel safe. Remember that home is a place where everyone wants to feel relaxed and safe.
- Explain that light trespass is a form of light pollution, but we strongly advise that you don’t threaten legal action. The idea of a lawsuit can create bad feelings among the whole neighborhood.
- Remember that everyone wants the same thing: a chance to relax in his or her own environment. Work together to create an atmosphere that benefits the community
- Write a letter. You may find it useful to put your thoughts on paper. We have provided a Sample Letter to Your Neighbor to get you started.
Impact of light pollution on plants
Figure 1. Light pollution and falling leaves: although the photograph was taken in late autumn, this tree has kept the leaves of the lower branches lit by a single light source embedded in the ground. The leaves on the upper branches, i.e. further away from the light source, have fallen off. Photograph taken at Square Dutilleul, Lille. [Source © Lamiot (CC BY-SA 3.0), via Wikimedia Commons]. Plants, like animals, are sensitive to light, its colour, intensity and duration of exposure. Thus, blue and red lights of high intensity are required for photosynthesis (link to article “Light on photosynthesis”). Low-intensity red and infrared lights regulate biological rhythms and control processes such as seed germination, stem elongation, leaf expansion, flower development and dormancy. In most cases, the intensity of light pollution is not sufficient to affect photosynthesis. However, by altering the day/night perception of plants and artificially increasing the length of the day, it can inhibit the dormancy of plants that allows them to survive the harsh winter. It can also promote leaf expansion and thus increase plant exposure to air pollution and water stress. In urban areas, it is possible to observe a delay in leaf fall for trees located near streetlights (Figure 1). For example, in New York (USA), leaf fall can be delayed by more than a month compared to surrounding areas ,.
References and notes
 Chaney W. (2002) Does Night Lighting HarmTrees? Forestry and Natural Resources, 1-4.
 Rich C. & Longcore T. (2006) Ecological consequences of artificial night lighting. Island Press.