A secret to growing nasturtium in a window box?

[Elena Zimmerman]

It never worked for me in the past. They grew just fine in the yard, but not in the box. Someone mentioned to me that you need to add the crystals to the soil to retain moisture better. How much do you need to add? And will that help nasturtiums?

If not, what fast growing from seed (imperative, our summer lasts from June to September tops!) annual that can be grown in a cheap plastic window box, exposed to prairie sun and high winds and an occasional heavy rain/hail would you recommend? It doesn't have to flower, just look nice in an off-white plastic box.

[haili]

They tell you not to fertilize nasturtiums but mine weren't blooming one year and I gave them the stuff with the 60 middle number and they bloomed really well after that. They did pretty good in the window box. I haven't grown them for years but have some in a new flower bed this year. They look healthy but if they don't bloom soon, they're getting a shot of fertilizer.

[Elena Zimmerman]

We didn't get to blooming with mine, they just remained small and stunted and pale and didn't grow anywhere as much as the ones in the yard from the same seed.

[haili]

If your container gets lots of sun and enough water they should do OK. Maybe a different kind of planter soil would help. I had good luck the year I grew mine in a window box and I just buy whatever planter soil is on sale - usually from Loblaws or Terra.

[Laura]

I am growing some nasturtiums in pots this season.This is my first time growing them.I read in Canadian Gardening that they do not like rich soils so I put them in old soil from three seasons ago and they sprouted and look really healthy.

[Elena Zimmerman]

It's probably water... I will try one experimental box with those crystals in, so they retain water. Once summer gets going here, the amount of sun is huge, so I will know for the next year if it worked or not.

[orchidguy]

Elena
Something I do in every planter and windowbox is add a layer of cut up (cheap) cellulose sponges on the bottom of the planter, and a layer of sphagnum moss on the top of the soil. When the spent soil is added to the compost pile in late fall, both the sponges and the moss have totally disintegrated by then. I still use the addition of crystals, just in case.

[Elena Zimmerman]

Oh, great idea about the spounges, I will definetly try it. I discovered the pit moss this year when I was building my lasagna beds, and was adding it to all my containers this year (the wooping 4 of them!), so I will definetly add some for nasturtiums. But most definetly will add sponge, I can see how it would regulate drainage.

[weliss]

That's interesting about the sponges, never heard of that before!
I've grown nasturtiums in my container garden for 4 years now and never had any problems. I mix old soil with new potting soil, and add peat moss every year. Plus I fertilize at the start of the season, but that's about all.
I have noticed that ones growing in a garden bed do better and clump more nicely than my balcony ones.

[Laura]

I mix old soil with new potting soil, and add peat moss every year. Plus I fertilize at the start of the season, but that's about all.

I was not sure about fretilizing them but did once through the summer.Will remember to do this more next season.I must say mine started blooming and have not stopped yet ... a great flower for sure.