Search This Blog

Wednesday, September 9, 2015

DIY: Reflective Grow Shelf

Seeds waiting to germinate in the grow tent.
Here in zone 5b Michigan, the average first frost date occurs somewhere between the last week in September and the first week in October.   Although we have had a few 80F (27C) days lately, the cold weather is closing in fast.  This means that the houseplants that have been "vacationing" outside need to come in to the house soon.

As the weather gets colder, the days get shorter as well.  This means that there is much less light than is optimal for most plants.  So what is a gardener to do?

The answer: Grow lights.  These are full spectrum light bulbs that can be used to either supplement or replace the natural sunlight in the winter.  Better Homes and Gardens has a good article about how to choose a grow light.  To read it, click HERE.

In addition to the grow lights, it helps to have a reflective "grow tent" to bounce the light from the full spectrum bulbs towards the plants and to optimize the amount of light that the plant receives.  But these grow tents can be expensive!  New, they may cost anywhere from $70 to $500 before you even purchase a grow light. 

But not to worry! I have found a way to create an inexpensive DIY grow tent.  The whole thing cost me about $40 including the lightbulbs!  However, I did have an old shelf available. If you do not have an old shelf, the whole project may cost you $40-$70 depending on where you purchase a second hand shelf.


Step1: Assemble the old wire shelf

 1. An old wire shelf -   The pop-together shelves used in dorm & children's rooms work perfectly for this.  You may have one of these sitting around.  Otherwise, you can probably find one second hand in a garage sale, Salvation Army store, or on sale at a big box store for a price range of $0 to $30.

2. Three full spectrum light bulbs - You should be able to find these in a pack of 3-4 for a price range of $3-$10.

3. Three bulb sockets with cords.  I found these online for $8 each.

4. The handyman's best friend: DUCT TAPE!  You can get this at the dollar store.

5. Three or four mylar emergency blankets.  You can find these for $3 each or less either online, at most drug stores, or at a big box store. (Note you may need more for a very tall or wide shelf.  The shelf I used was about 2 ft. x 1ft x 5ft)

6.  A couple of zip ties - You can find these at the dollar store.

7. An extension cord or adapter plug - optional.  This should cost less than $5 and can be found at any big box store, or perhaps your dollar store.


1. Assemble the shelf per shelf instructions.

2. Attach the bulb sockets to 3 tiers of the shelf using zip ties.  Run the cords along the outside of the shelf.  If you want, you can zip tie the cords in to place as well. Hang the bulbs so they do not touch the outside edges of the wire shelf.  This is in order to avoid making contact between the bulb and the mylar sheeting.  If the mylar heats up, it could melt or possibly burn.  Please use caution, common sense, and cool light bulbs.  (NO HEAT LAMPS!!!!!)
Step 2: Zip tie sockets to wire shelf

3. Screw the light bulbs in to place.

4. Use 2 of the 3 mylar emergency blankets to wrap the outside of the shelf.  Secure the mylar in to place with the duct tape. Wrap the left side of the shelf with one mylar sheet, and the right side with the other, leaving an open, over-lapping seam up the center of the back of the shelving so that you can access the pots from the back of the shelf. Be sure to cover the top of the shelf entirely. This step is fun because it's a bit like wrapping a giant Christmas present!!  :) :) :)    (See picture below.)

5. Cover the bottom shelf with the 3rd mylar sheet to reflect light upward into the shelf from below. Tape this in to place with the duct tape.

6. If you are placing the shelf against a window, leave one side of the shelf open / NOT covered by the mylar.  Place the shelf so that this open side faces the window to collect as much natural sunlight as you can.  A south-facing window is best, but any window will do in a pinch!

Step 4: Wrap the shelf in mylar. Leave an access opening in back.
7. If you are placing the shelf in a basement without a window, then go ahead and cover the shelf entirely with the mylar using the 4th mylar sheet.  If you choose to do this, you may want to consider which types of light bulbs you use as grow lights a bit more carefully.  The prices for these can range into the $100's and vary considerably in power, and light spectrum. Better Homes and Gardens has a good article about how to choose a grow light.  To read it, click HERE.

Step 6: Wrap the shelf in mylar with one side open for placement towards the window
 8. Plug the bulb sockets in to the wall or the extension cord.  Make sure that the bulbs are securely in place and turn them on!


Place the plants or pots on the shelf.  Try to load the shelf from the bottom upward so that it does not become top heavy and tip over.

You can use the shelf either to help keep your house plants happy through the winter, or for seed starting in the early spring (or any time of year, really!)

Most plants need about 12 hours of sunlight per day.  If the days are long enough, and the light bright enough, you may be able to leave the lights off for a time.  Once the days shorten, simply turn the lights on in the shelf in the morning and then turn them off 12 hours later.

Remember, in Michigan, the fall equinox is September 23rd and spring equinox is March 20. So you should certainly turn your grow lights on between 9/23 and 3/20 to supplement for the shortened day / missing sunlight.

If you are forgetful, you may want to plug the extension cord in to an electrical timer set to turn on and off every 12 hours.  These timers cost as little as $4 at a big box store.  Well worth the savings to your electric bill!

Note:  The shelf does not insulate very well, and it is dangerous to use a heat lamp with the mylar (fire & toxic fume hazard).  If your plants require a certain temperature, please control this via the central heating system of your house.


Follow me via:
Twitter: @alhramAndrea
Pinterest: @MiLakeGarden
Facebook: Mi Lake Home Garden
Instagram: @MiLakeHomeGarden

No comments:

Post a Comment