I have cement block raised garden beds also and with the right mix, it drains but retains moisture so I would not worry.

Penny

If you went with a true Mel's Mix formula, you should have no problems. I have a 16'x3' raised bed on concrete and it actually drains the best of my raised beds. I actually look forward to the rain. Something about natural rain water seems to inspire growth within the plant and I get a huge growth spurt as soon the clouds clear to that full sun.

good luck!

If you see a lot of water pooling where the seedlings are, you can expect high attrition, though usually not 100% unless its sustained bad flooding for several days.

You'll know the full damage in a week or so. If there is damage, the newest seedlings will be the worst hit, but they often surprise you and recover a few days later. Plants that have well-established true leaves will tend to survive better.

After the rains stop, you may want to check and see if some of your seedlings are buried under soil that got tossed around by water. If they are, try to VERY CAREFULLY expose them, while keeping their root portions covered by soil. If you just see some accumulated splashed earth on their leaves, leave it for a bit and hose it off later once the ground has dried out some.

We all had this experience about 3 years back when we had some REALLY hard rains in LA. It took out a lot of seeding plants in February, even in raised beds with "pretty good" drainage.

Anyhow, your raised beds should be fairly resistant -- this is one of the reasons you make them. That being said -- if you are seeing ANY sign of pooling water that is lasting more than an hour or so, and you have an easy way to keep water off the beds, go for it.

Worst case though -- can just replant. You aren't going to lose that much harvest or time at this point, and if you are super concerned, you can always just order some seedlings to make up the lost time either directly at the store or via mail from a nursery.

Good luck! Hopefully your beds manage the damage.

This post was edited by Thuringiensis on Sat, Mar 1, 14 at 3:43

Oh and -- with a lot of the plants you are mentioning (carrots especially come to mind), if you did it right, you over-seeded them anyway, so this may just end up saving you a little bit of thinning effort.

Rain brings nitrates, which are created in the atmosphere by lightning.