1st time grower here after a bit of advice regarding temperature. Seeds have all sprouted and are about 2-3 weeks since seeds were planted. The have their first pair of real leaves and all still have the cotyledon leaves. They are about 1.5-2 inches tall. However I am concerned that something is stunting their growth as I’ve seen many seedlings of this age with more sets of leaves. It is an outdoor grow, but they are moved undercover and put under a frost blanket overnight. When the days are sunny they are in full sunlight all day. I know that if temperatures drop below 60F (16C) they may stop growing completely, they are in a temperate - cold climate and at the beginning of spring. Daytime temperatures have been around 16-19 Celcius (60-66F) and overnight temperatures dropping as low as 3C (37F). When weather heats up hopefully coinciding with the vegetative and flowering periods daytime temperatures are usually around 70-80F. So my questions to you all is… Are these temperatures too cold for efficient growth during the day? If necessary, what can I be doing to keep them warmer during those cold night? Are they going to be okay? Please take into consideration that a heat source in the form of a light isn’t possible in my circumstance.
Strains are Gold Leaf and Super Skunk.
Thankyou very much in advance for any helpful advice.
Couple things worth mentioning.
I’m not sure where your located, but outside growing season is commin to an end, in the Northern Hemisphere. Soon frost will set in, if it hasn’t already.
People that have outside grows normally plant in the Spring, not a week after Fall starts.
Plants take about 90-120 days on average, depending on strain and preferences. You’ll be well into winter before harvest, and probably freeze.
Light will also be an issue, entering into winter, sunlight becomes more limited. Bud density will be effected, and possibly under a development in Veg time, triggering an early Flower period.
Yes, any temperatures in the lower 60’s and nutrient processes are limited. Unless you have a heat plan (ie, moving you plants to an inside grow) you can expect your plants to not make it.
Yes indeed, however I should have mentioned previously but growing in Australia so at the beginning of spring heading into summer in a couple of months.
So based on this information what do you guys reckon about my previous questions?
Cheers
That makes a big difference.
If nights get cold, you may have to cover them. If frost sets in, nicrosis will occur. If I were you, I’d still bring them inside until frost isn’t an issue.
Happy growing, mate 
Champion. Have had them inside near the hot water tank to keep them warmer overnights. Cheers
Good stuff Dumme.
Below 60f, and above 80+f and the photosynthesis slows down.
Below 50f and cell damage occurs. Below 40 and the plant starts to die.