|
Post by spacecase0 on Dec 29, 2017 19:59:12 GMT -5
so I have a question about germination temperatures, my soil temperature changes 40F day to night, so when the chart says 75F (just a random example), should this be 95 to 55F ? or should be 75F to an overnight low of 35F ? I seem to have failed at any range I can find, so I am kind of wondering if my day to night temps are going to make it not possible to get germination from something like turnips (and yes I mostly want turnips to germinate)
|
|
|
Post by Gianna on Dec 30, 2017 0:09:05 GMT -5
Where do you keep your germinating seeds that you get that great a temperature range? You said 'soil temperature' so that may mean outside. Can you put the seeds in cells and someplace inside that is more constant? Then transplant? 95 seems like a high temp for something like turnips - a cool weather crop. I just planted some a few days ago, inside, in soil blocks, and got good germination. I'd guess the temp range was somewhere between 70 to maybe 55 (unheated house, near a sunny window). Cool weather crops such as lettuce and spinach don't like higher temps for germination. Maybe turnips too. Things that like higher temps to germinate, like peppers and tomatoes (always germinated in cells), do very well at about 80F. (I don't know what's recommended for them, but 80 works great for me.) I would never let them drop 40 degrees or I'd probably run the risk of failure. I don't even like them to drop 20 degrees overnight, hence added heat for these. Unless you are germinating small seeds outside that are right on the soil surface, the range would not be so great. The deeper the seed, the less the temp extremes. Interesting topic - I look forward to reading other responses.
|
|
|
Post by brownrexx on Dec 30, 2017 9:27:28 GMT -5
I was also very surprised to hear that soil would change 40 degrees overnight. Soil is a good insulator and usually does not change temperature that quickly although maybe the area is in full sun and the seeds are not very deep. spacecase0, you do not give your location, I am wondering where you are located? If strong direct sun is affecting your soil temperature then maybe you could cover your seed bed with something like a board to insulate it from the sun until the turnips germinate. I have heard of people doing this to get carrots to germinate. It also keeps the soil moist which also helps with quicker germination.
|
|
|
Post by paulf on Dec 30, 2017 10:32:43 GMT -5
For best germination rates, start cabbage seeds in seed flats in a greenhouse or other protected area. Cabbage seeds germinate in soil between 50 and 85 degrees Fahrenheit and take four to 10 days to germinate. The seedlings take five to seven weeks to grow big enough to plant out in the garden. You can also plant cabbage seeds directly into a prepared garden bed as soon as the soil warms to 50 degrees.
Cabbage germination occurs on a bell curve. At soil temp of 32 there is zero germination
41 degrees---27% germination 50 degrees--78% and germination takes 15 days 59 degrees--78% and 9 days 68 degrees--93% and 9 days 77 degrees--99% and takes 5 days----this is the optimum soil temp for best germination at the shortest time 86 degrees--0 germination
|
|
|
Post by paquebot on Dec 30, 2017 10:35:46 GMT -5
If there is a lot of variation between day and night temperatures, germination date will be somewhere in between. Just about every vegetable will germinate at 95ºF. (Turnips will do it in one day.) Most also will germinate at 45º. (Turnips would take 5 days.) Not many are going to germinate below 40º and those that do take a long time. (Carrots would take 50+ days at 40º.)
Martin
The truth is more important than the facts.
|
|
|
Post by Gianna on Dec 30, 2017 13:36:47 GMT -5
There are so many variables to germinating seeds. Temperature of the air and/or soil. Soil type, plus moisture, plus how deep you are planting the seeds. Not to mention the genetic requirements of each variety.
Some of these variables are more pronounced outside since we can't control the weather. To help limit the variables, and if you are inclined, start your seeds inside (or in an enclosed place outside) where you can control more factors such as soil type, moisture level, temperature, and light. Might as well stack the germination deck in your favor as much as possible.
|
|
|
Post by paquebot on Dec 30, 2017 16:17:25 GMT -5
Ideal temperature for most vegetables is between 75º and 80º. Maintain that range for both maximum percentage and minimum time. If lower, there may be more that abort. Prime exception is spinach. Ideal is between 40º and 50º.
Martin
The truth is more important than the facts.
|
|
|
Post by spacecase0 on Dec 30, 2017 16:31:34 GMT -5
I am almost in the geographical center of california it is up in the hills, so it cools off at night, in the summer I get +100F weather in the day, and 70F at night, spring and fall I get up to 40F change form day to night
the turnips are small seeds that I have to plant close to the surface, they don't grow in shade locations, so they are out in full sun.
from the replies, it sounds like I have to transplant them all maybe some years I can direct seed, but this year went from so hot I was melting in a short sleeved shirt to finding the warmest coat I could find with only one day in the middle when it changed.
I next fall I will try covering them to make the temp more stable
|
|
|
Post by paquebot on Dec 30, 2017 21:41:54 GMT -5
Space, if your turnips are not germinating in the ground, there's something drastically wrong. Since turnips have a very wide range of temperatures for germination, that should be no factor. Almost any soil would be OK unless it was very alkaline.
Martin
The truth is more important than the facts.
|
|
|
Post by spacecase0 on Dec 30, 2017 22:15:58 GMT -5
soil here is a bit acid if anything, but I will test that spot just to be sure, I even tried potting soil got seeds from multiple sources in case one batch was bad... will keep searching for what went wrong somewhere other than temperature
|
|
|
Post by paquebot on Dec 31, 2017 8:20:32 GMT -5
Turnips, like most other vegetables, love acidic soil. The range for turnips is 5.0 to 7.0.
Martin
The truth is more important than the facts.
|
|
|
Post by brownrexx on Dec 31, 2017 12:34:54 GMT -5
I would try germinating a few seeds in a wet paper towel just to see what happens. Just keep the towel wet and you should see if it germinates in a couple of days in doors with steady moisture and a steady temperature. This will tell you if your seeds are good
|
|