Question
QUESTION: Hello,

I recently purchased pink, white and purple petunias to put them in window boxes. This is my first time planting anything so i really tried my best to get all of the supplies i thought i was going to need. I planted about 10 petunias into one window box with coconut liner then i added miracle grow potting mix with moisture control and slow release fertilizer. After only two days, i started to notice  that some of them started to look a little droopy so i took them out and replaced them with new ones, this time i added miracle grow fertilizer with slow release up to 3 months. Then i planted the rest of them into the second window box, this time i only added about 6 plants to it because i thought maybe the i made a mistake in planting too many into the first one. I repeated all the steps, added soil, then fertilizer then the plants and then more soil on top to cover the roots. I added a little more fertilizer on top of it just in case it wasn't enough and then i watered them. The next day i woke up and saw they were all starting to look droopy again, i left them alone and didn't water them because i didn't think they needed any water. Today i came home from work and they were pretty much dead, i felt the soil and it seemed pretty dry so i went ahead and watered the first window box that is doing ok but not so well. I would like to get some advice on what to do about this problem. I love flowers and i really want to keep planting them, i just want to learn how to take good care of them without giving them too much or too little care. I live in California and right now we have 85 to 95 degree weather. I do have the window boxes out on my patio so they get a lot of shade, probably about 4 hours of full sun a day. Please help!!! I really need your advice.

PS
In case i have to replant new petunias, should i get rid of all the soil that i put in the boxes and use new one?

Thanks so much!

-Lizeth

ANSWER: Lizeth,
First of all, know that some plants wilt after planting them because the process of taking them out of the six packs or pots shakes up the roots and stems and then they have to recover and adjust. If you used new potting soil that is perfect and if you have a cocoa liner there should be good drainage. Is the cocoa liner inside a box (wooden? plastic? metal?) that has drainage holes?  As long as the water can drain out of the box, no matter what it's made of, it should be OK.

You may have used too much fertilizer - if the spoil you planted in has time-release fertilizer mixed in, you shouldn't have to add fertilizer for another six weeks to two months. Too much fertilizer can burn the roots of the plants. In the boxes that have dead plants, perhaps you could scrape off the excess time-release fertilizer if possible - I'm assuming that the fertilizer you used is the time-release pellets, yes?  In the future, wait until the plants get established and start growing before you add any fertilizer, and then follow the directions on the package as to amounts.

When you plant, try not to damage roots and stems too much - if they get bent or broken the plants will wilt.  After planting water well to soak all the soil in the box (excess will drain out of holes/slots in the box) and then don't water again until the soil feels dry. A good deep soaking less often is better than a little every day or every other day. If your plants get sun in the afternoon when the sun is strongest you might need to water in the evening instead of the morning - if so, try not to get the foliage wet.  

Be sure that when you plant you don't pack the plants in by patting the soil down... this compresses air out of the potting soil and might damage roots as well.

I hope that this helps, but if you need to give me more details or need more feedback please let me know.
C.L.

---------- FOLLOW-UP ----------

QUESTION: Thanks so much for your quick response C.L!

I actually have the cocoa liner inside a metal boxes so it should get pretty good drainage and yes, i have the slow release pellets. I also bought liquid plant food that i haven't used yet and i was wondering if and when i should use that and if i could use both or just one. The boxes get sun early in the morning, probably from 8am to 11am or 12pm. Should i still water them in the evening? I will try to get new ones and plant them in the second box without the fertilizer.

Thanks again! = )

-Lizeth

Answer
Lizeth,
Be sure that the metal boxes have holes in them... if they don't, they will hold water and keep the soil too wet despite the liners.

If you've used the time release fertilizer you shouldn't have to use a liquid for at least 6 to 8 weeks. If after two months the plants start to slow down, you can give a liquid after watering the plants well - never fertilize a thirsty plant.

Since they are in morning sun you should be able to water them once a day but I'd stick your finger in the soil to check and see how dry it is - do this in the morning and evening, and water if the soil is dry down two inches below the surface. The plants will use more water after they grow larger and have a bigger root system, so as they grow you might have to water more often. Don't water if the soil feels damp - let it dry out a bit, but water before the plants look wilted and limp. (By the way - wilting, limp plants can also mean too much water - if the soil is kept too wet the roots will rot and the plants will wilt, so don't assume that if they look limp they are dry... always feel the soil before watering.)

If you have Super petunias or Wave petunias they won't need deadheading (they would be labeled as such and come in pots not in six packs)  Other petunias need to have spent flowers clipped off by snipping the stem that is below the flower. This takes off the developing seeds so that the plant will continue to make flowers.

I hope this helps!

C.L.