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Pros and Cons of Self-Watering Systems for Window Boxes

Self Watering Systems for Window BoxesWindow boxes by their nature need to be watered frequently, especially in the dog days of summer. Often the limited soil volume dries out daily. Today’s busy lifestyles make daily watering a challenge, however new innovations mean you can buy a number of systems that will turn your window box into a “self-watering window box.” Let’s look at the pros and cons of several self watering systems on the market.

Watering Globes

The globe system is simplicity itself. Watering globes store water and slowly drip into the dirt to help water a window box. They have a slender stem that limits water flow. You fill up the globe, insert it into the pot and as the dirt near it gets dry it absorbs water that is gradually dispensed by the bulb.

Pros for this system:

1. Glass globes are cost effective ways to keep your plants watered.

2. The glass globe approach has great variety in color and shape to suit each person’s taste. They can enhance the visual appeal of your container garden.

3. This system’s limited water capacity prevents overwatering and root rot.

Cons for this system:

  1. The narrow stem can make the bulbs challenging to fill. The design limits water flow in as well as out.
  2. The narrowness of the stem makes it easy to clog or break. You’ll want to make sure they are not clogged before you leave your plants to their care and go on vacation.

Watering Spikes

Spikes use the same approach as globes but utilize plastic bottles you already have to hold the water. Watering spikes attach to a plastic bottle (up to 2 liters) which then is flipped upside down and placed in the soil. It works by slowly dripping from the bottle to the soil and the nozzle regulates water flow to a slow drip.

Pros for this system:

  1. Spikes combined with something out of your recycle bin can create the least expensive watering system.
  2. Due to the water being added to a relatively wide mouth container adding water is easy.
  3. If you just chose a transparent bottle monitoring the water level is easy.

Cons for this system:

  1. While using water containers you have on hand is cost effective it is not visually attractive. To cover a long window box, you can end up with multiple 2-liter soda bottles sticking out of your window box.
  2. A full 2-liter bottle weighs more than 4 pounds, which can make balancing these water sources challenging as they are top heavy.
  3. In general, the spikes dispense their water in the top half of the container, which means they do not promote deep root growth.

Drip Irrigation Kits for Self Watering ContainersDrip Line Irrigation Kits

Drip lines allow the DIY container gardener to install a fully automatic watering system at a significantly reduced cost compared to professionally installed irrigation. It consists of a kit with dozens of drip emitters and small tubes that are spliced together. Once you have the drip rate adjusted correctly for the window box, your faucet sends a continued drip into the box at several drip points and you are set until the season changes or the plants grow enough to have increased watering needs.

Pros for this system:

  1. For the container gardener who wants to not be responsible for the life of their plants this option is the most economical.
  2. Unlike irrigation from a container, this option continues to water as long as you need it to.
  3. The hardware purchased for this system allows you to control the drip rate so you can adjust the water flow when the weather warms up or the plants grow bigger.

Cons for this system:

  1. Since these emitters are fed by tubing, you will have to be creative to hide the tubing from sight.
  2. This system does require a significant initial investment in time and DIY skills to install it.
  3. The hands-free pro can become a con if you have significant rain and you do not have sufficient draining, resulting in potential root rot.

Professional Drip Irrigation Systems

  1. Having a professional irrigation company install and maintain your watering system is the least investment of labor by the homeowner.
  2. Generally, the installers of these system will monitor at least initially to ensure your box is getting the correct amount of water.
  3. Professionals can provide water to each window box in discrete ways such as pipe, sprinklers, or tubing.

Cons for this system:

  1. The biggest con for this system, is usually the expense, which can be significant.
  2. If the professional system is directly piped into each box or covered by a ground sprinkler, professional labor is usually necessary if you chose to move planters around.
  3. Most watering systems installed as part of the irrigation plan in your landscape are not flexible to allow you to rearrange your containers to change up your landscaping.

Self Watering Reservoir Systems for Window BoxesSelf Watering Reservoirs

This system is an easily installed or easily removed reservoir system that can decrease watering frequency by one-half or even one-third. Since it is inside your containers and under your soil and plants, reservoir systems leave your lovely plants not only healthy but what everyone sees in your box.

Pros for this system:

  1. Accommodates busy lifestyles while keeping plants looking great by allowing you to only water once or twice a week.
  2. Easily winterize your reservoir by simply not continuing to put water in it.
  3. Since this system is at the bottom of your containers, it encourages deep root growth and that makes for healthy plants.
  4. Each system is purchased in a size made for the box it is used in, so no guess work to figure out spike density or rate flow.

Cons for this system:

  1. This system is not visible once your window box is planted so there is a learning process adjusting water frequency needs to each box.
  2. Since the water is in the bottom pipes only, you must learn to observe water level.
  3. A sub irrigation reservoir requires once a week refilling.

In conclusion, having plants that need to be watered daily calls for a self-watering system. Each of the systems discussed have both pros and cons.