Monday, April 06, 2020

Make sun shades for indoor start seedlings, prevent sunburn!


Are you ready to garden this year?
Our calico cat is, and she swears she's helping.

I am going to show how to make a cheap effective sun shade, to prevent sunburn on your newly transplanted indoor seedlings.

This is very important!  A lot of people will sunburn their seedlings without knowing it, because they forget to harden them off - or they buy them from a hothouse that did not harden off properly.  Sometimes, the sun is just too much for an indoor-raised plant.  It will show by bits of the leaves turning white or pale yellow and flaking away, like brittle paper.

To help prevent it, we are going to try to block some of the noon and afternoon sun from hitting the plants full force.




It is also important that this be a light colored, but not bright white cloth.  Bright white will send too many rays reflecting back off the cloth.

I grabbed this cotton cloth because it is handy.. and I don't care that it will not survive to next year.  The sun will damage the cloth over time and make it brittle, too - but by then, your plant will have grown up healthy, we hope!


Cut a rectangle off your fabric about as wide as your tomato cage and at least as tall, maybe more.  Cut an inward gash on all four corners, but not too far, as you don't want the fabric to tear completely and the strip to come off easily.


Now you will tie the top two strips to the wires above your plant, creating a little 'tent' for it.  I do this on the WEST side of my plants, because I have trees to the EAST that block most of the bright morning sun.  If you pull the fabric a bit over the middle of the cage as well it will block direct noon sun...

If you are out in the open and need protection on both sides - make two shades, one for each side, or tie the rectangle more over the top - we aren't blocking all the sun, just the hottest sun so that the plant can have a rest.

In some years when I only had one or two plants I would set up a few buckets and a board on the west side and be done with it - but this is the way to ensure each plant gets some shade when it needs it most.



Just loop a slip knot around the wire and then pull it shut - but not too tight, as it could tear.


I usually tie the bottom ties as well, positioning the shade so it blocks most of the sun at 2 or 3 o clock in the afternoon, putting them out about this time will ensure you are blocking the light all the way to sundown.  


You can do this with old shirt fabric or an old sheet and protect your time investment in your seedlings.  Sometimes I will tear up some of these shades later to help tie bits of vines loosely to the cage, once the plant is big. 

The other tips I got from my mentor was to bury my tomato seedlings 'all the way to their ears' in the hole, but not with the leaves actually touching the soil!  If the leaves touch the soil that keeps them moist with dew and that can invite viruses and bacteria to the plant etc.  Add a little loose dirt and water at the bottom of the hole, and then put the seedling pot contents into it.  Gently press loose dirt in and around the seedlings pressing the outer corners of the pot soil down into the dirt, while trying not to break the stems of the seedlings.

Sources :

I was taught to do the sun shades by Tom Carpenter, of the University of Minnesota Experiment Station, way back in 1994 when I was at one of my very first employments.  He had also had my father on the farm when I was a small child and he was in the National Guard with Mr. Tom.  I was proud to hear about the gardens, see my father's picture on the wall and learn the different ways to take care of plants.  The plants we made 'much larger' sunshades for were delicate shade plants that were part of experimental seed trials.  But, he explained to me it could be done for even a small plant or with a large sheet for an entire area, as long as it was secured well, and to take it down in a high wind or heavy downpour.

 My 'bury them to their ears' comes from Mr. Harold Cole who I worked with at Lowe's.  It was a long time ago, but once in the breakroom he was talking about planting and gardening and I was all ears. Ha!  He said the plant will grow extra feelers / suckers in the stem to take in more nutrients and be stronger if you bury it all the way up to the leaves delicately and water it in gently.  He said he planted 90+ tomatoes every year from seedlings!

Also be sure to water your plant in and check on it the next day and the day after that.  It is only common sense - but you want to make sure the shade has not been torn or blown away.  And remember if it is going to rain hard you will want to maybe put a 5 gallon bucket over the top of your seedling and 'squidge' it in to the soil (so it doesn't just collect water under the edge)  Remove the bucket as soon as you can - or it will get hot under it the next day.

Enjoy, good gardening!

1 comment:

Gale said...

Very good advice for those of us that know virtually nothing about gardening. The pictures help so much to show how to do it and what it should look like afterwards. Thank you!!