Saturday, November 12, 2016

Direct Sowing Fine Seed

Except for radish which germinate quickly, I find that I need to give some sort of extra care to small and especially fine seeds that I sow directly into the garden beds. Otherwise they tend to germinate very poorly. I suspect it is the tropical wind and sun that is too harsh in my conditions, 

Fine seeds, I find, are by far the most difficult. There are a number of ways a person could give them some protection. I've tried a few methods but they haven't been the solution I'm looking for. 
1- Covering the seed with a thin layer of fine sand. This method hasn't helped. The surface still dries out too quickly. 
2- Covering the seed with potting soil. Ditto, as above. Things dry out faster than I can keep up with. 
3- Multiple light waterings during the day. While this works, it's real difficult to stop what I'm doing in order to run down to the garden and water a bed 3 to 5 times a day. So I'm looking for a better solution. 
4- Provide shade cover. I've done this with some success but discovered that more needs to be done. Shade alone isn't enough. 

What I'm currently trying is covering the freshly seeded bed with a white sheet. I then remove the sheet each morning, water the bed, and replace it. 

Above, I've pulled back one sheet and started to moisten the soil surface. One half of the bed is dark colored (wet) while the other half is lighter (dry).

Above, this bed is now completely watered and ready to have the sheets put back on top. 

Above, with the sheets in place, I wet them down before calling it a day. 
This seems to keep the seed moist all day long. I'm just now trying this method with carrot and parsnip seed. Give me a couple of weeks and I'll let you know how it's working. If I can get away with watering just once a day, it's acceptable to me. 

I've successfully germinated fine seed before, but it's been in a shaded greenhouse situation. I watered once a day each morning. The greenhouse humidity plus protection from the sun & wind worked well. But I want to figure out a good system for direct sowing fine seeds into the garden bed.

I'm thinking out a system using simple removable hoops for making a low tunnel arrangement for some of the garden beds. I see lots of examples of low tunnels using poly film or reemay cloth, but they're awkward, difficult, and time consuming to open daily for light watering. Another idea is removable, light cages with sheet coverings. Yes, you can't envision them yet and neither can I.....there's a significant problem with the idea. They are lightweight making them easy to remove and replace quickly, but thus also susceptible to having the wind blow them away. Ah, my mind is spinning.  We'll see what my mind comes up with. 

Before everyone floods me with email suggestions of using a sprinkler system or misting system, please keep in mind that I am on a limited solar electricity. Plus my water pump is a low pressure, low flow one. Besides, most of the garden beds are too far away from electricity and water systems to install a sprinkler or mister set up even if I wanted to waste the electricity. One more thing, I'm not on municipal water. I catch rainwater off the roof and store it in a huge tank. Thus water available for irrigation is limited. With significant limitations in the amount of power, water pressure, and water volume that I have to deal with, I need to think out alternative solutions. 


  1. Lucky you live Hawaii - maybe try overlapping the wetted sheets with palm fronds, pegging the stem ends to the ground or weighting them with rocks, or lashing thin poles together, or to the fronds?

  2. I think the sheet is an ideal barrier to wind drying. it allows the water in and some light but once it drys it no longer wicks water up to the drying wind. Spun bond fabric might be more effective but it also may trap too much heat from the sun. I may use this to prevent little birds from eating my seeds.