Effect on area flooding right after planting seeds and onion sets


Today (May 7) a few hours after planting onion sets, radish seeds, and leaf lettuce seeds part of one small area I planted pooled from a heavy rainfall that fell. This occurred in one of two small areas where grass was dug up. Topsoil specific to gardens was added before planting. The soil before this addition is on the clay side. The other area – also dug – was fine. Will the seeds and onion sets survive and grow into plants and if they do are they safe to eat? Area is sunny all day from sunrise. What can I do to prevent this happening again? This pooling situation has never happened before anywhere in my garden and I have been gardening here for many years. I am in Zone 5 by USDA terms, in Toronto so near Lake Ontario. We did get five or six days of some rain last week, but weather was dry the past couple of days and soil not wet when I planted the onion sets, radish and lettuce seeds late this morning. The pooled water is now gone and the rain has stopped. Photos probably wouldn’t help in these circumstances because of the pooling being gone. I did go outside and check it a few minutes ago but did not touch the soil there, but it is probably still saturated.

Thank you.


Sorry to hear that your garden took a beating from the heavy rains in the Toronto area this past week.

Seeds: While planting seeds before a light, soaking rain can be a good plan, pounding and heavy rain can easily wash seeds right out of the soil.  Given that there was standing water and puddling in your garden, it is more than likely that the seeds have washed away or they may have all clumped in one area.  You will likely have to re-seed your lettuce and radishes.

Onion sets:  The onion sets should be okay.  They have likely been pushed around or up out of the soil due to the rain.  When the soil is not waterlogged, just place them in the soil again  and add a bit more soil around the bulb, so that the bulb is just showing.  Be aware that soil that is too heavy or moist can stunt their growth and/or cause them to rot before reaching maturity. As with germinating seeds, damping 0ff and stem decay attack vegetable transplants struggling in compacted, poor draining soil so keep a close eye on drainage in your garden.

Drainage: As you discovered this weekend, it is important to keep a close eye on drainage in your garden.  In addition,  you are dealing with clay soil.  In the long term, there are strategies to amend clay soils:

Toronto Master Gardeners: How to fix clay soils

Continue to pay attention to  the hydrology of your garden…where does the water flow?  Check for erosion after heavy rain: where is the soil running off?

To improve drainage you can create ditches, streams or trenches to direct run off.  Do not plant in the areas that don’t drain.  In these areas you might consider building raised beds.

A simple way to improve the drainage in your garden bed is to use a garden fork and work through the area.  It is not necessary to turn over the soil thoroughly…just add air pockets with the fork so that the water has somewhere to flow.

Hope you have great success in your garden.