Desiging an outdoor grow in hot, dry, desert climate

[LiveFreeOrDie]

I've been reading some threads on outdoor growing. I'm currently designing a outdoor grow for this season. Could use general advice for my first non-guerilla outdoor grow, particularly in a HOT, dry, outdoor climate.

Currently plan on growing four strains:
- Afghan Kush (100% Indica)
- Strawberry Diesel
- Lebanese (100% Sativa)
- Malawi x Panama (100% Sativa)

Currently I'm rooting new clones of the Kush and germinating new seeds for the other three. A little concerned about the pure Indica in this climate.

Climate is very hot (as high as 120F peak summer, dry, and with hard natural soil). I'm unsure the exact season, but one source indicated mid-late march is acceptable to move outdoors. It's already like 75F, so main concern is light schedule. Expected harvest in October, early November for pure sativas.

Next Steps:
- Root Clones/Germinate Seeds and keep under 15/9 lighting until rooted
- Pot and move outdoors end of March (too soon? Should I wait longer, particularly for the Kush that comes from a mother with a longer light schedule?)
- Determine optimal time to move outside. I imagine the sooner the better as long as I don't trigger flowering prematurely

Grow Setup Considerations:
- 4-6 Plants in either 25 gallon bags or in 4x4x2' containers
- Soil mixture: unsure, thinking a mix of top soil, natural soil, worm castings, bonemeal, mulch on top to reduce heat issues
- I will need a shade cloth in peak summer. Try to decide if I should build a shade cloth hoop greenhouse, or plant in area with natural shade and supplement with shade cloth

Any advice for my climate, setup, or preventing early flower? Nutes, pest control? Also, is it a bad idea to double/triple up plants in a 4x4x2' container? Will they compete too much?

Thanks gang.

 

[troutman]

Mulch heavy around the plants to hold moisture. Another thing, if I grew in a very hot place like you plan on to I would
place a shallow tray of sorts in the bottom of hole before filling it up so it could collect maybe 2 or 3 inches of water at
most. This would help a lot I think. Shading the pots if you grow in them will help keep the roots cooler.

 

[TychoMonolyth]

Get or make a good supersoil. Here's an easy one. It has to cook for 28 days, but you have time.


Don't put them out before the second week of May. Anything more than 14 hrs of daylight should be safe.
Check here for daylight hours for your location: https://www.timeanddate.com/sun/

Add water crystals to your soil. You'll need them when it dries. But don't go nuts with them. Make sure you hydrate them before you plant.

When it comes to a hole, wider is better than deeper. 4' wide x 2' deep is perfect. Make sure you have really good supports in place. Once they start packing on weight, you'll need it or branches will start braking, or worse, the whole plant will fall over.

Don't worry about shade cloth. Weed (like corn) uses all the sun you throw at it. The more the better.

Like troutman said, shade the ground. Using something like white or red clover seed from a nursery as cover crop can help. but anything you can shield the soil will help.

The more you water, the better your plants will do.

Good luck.

 

[LiveFreeOrDie]

troutman thanks for the suggestions. I definitely plan on using mulch. Currently building an experimental sub-irrigation planter in 5 gal buckets for non-cannabis garden plants. I may try a similar (but different) design for my larger pots/containers (when I transplant) if my experiment works well.

TychoMonolyth thank you so much. I'll get started on my soil. Does the light calculation date to move outside include the twilight period? If so I hit 14 hours in mid-April, otherwise mid-May. When can I expect the transition to flowering outdoors, once we drop below 14 daylight hours? I have more experience growing indoors - expected more veg time outdoors than two months. Sorry for the noob questions.

Appreciate the tips on wider rather than deeper and water crystals. I know a hole is better to control the temps, but I have several 4'x2' crates I was thinking of converting into large grow containers. I would do in-ground but the soil is extremely difficult to excavate. Is that a major problem if I'm on point with the other factors?

My region also has a brief but sometimes heavy rainy season. Typically we'll see 2-3 periods of 2-4 days of heavy rain and possibly strong winds (unless we're in a drought). It can last from late July to the end of September. I'll need to plan on not just wind, but rain during the first half of flower for the Sativas (end of October/early November finish) and for the complete flowering period for the Indica (end of September). Mold, pests, and storms destroying the harvest are all real, serious concerns. Hopefully it's less of an issue for the Sativas due to the late finish. Is this an issue that will require building an enclosure? What should my strategy be here?

 

[Creeperpark]

Growing in hot temps can be done, but there are certain principles you have to follow in order to pull it off. The strains you name above will need constant caretaking. You won't be able to plant them and then come back in 2 months to check on them later. Rainy areas are good for cannabis because of the lower pH from the rain. Here are the principles I used and got weed every year I grew. I grew in desert-like temps.

Build the soil in Fall and Winter by harvesting shredded leaves or grass clippings from the area and put in the plot. Organic stuff acks like a sponge and holds water in the ground.

When you open the ground in the Fall you start building a "water table" underground by all the annual rainfall falling to the ground. Maybe 20 or 30 inches?

When you put the plants in the ground you mulch the plant to conserve the water you stored in the ground during Winter.

Never let the Sun hit the ground always add mulch at least knee-high under the plants to keep them cool and hold water in the ground.

Try to have hidden, least two or three 45 gallon trash cans with lids full of rainwater from the spring for the dry times.

 

[TychoMonolyth]

I'd say 4x4x3 crates is probably better than a hole. Good on you. Wish I had some for my yard.

Go for civil or daylight. If you look at the far left, it's only about an hour between Nautical and Civil (A1).
This is my area. I could plant earlier, but I've been bitten too many time by hard frost that killed 200+ plants. I only plant half mid may, and the other half June1.

Something else that may be important to you.
It's better if your plant get full sun in the morning, than in the afternoon.

Note that the jig in the line March 13 and November is the daylight saving time switch.

 

[troutman]

In my area planting outdoors before June 10th can be risky. It's tempting when the end of May can be
nice and warm. But early June tends to bring in one last cold snap and that's where things go wrong.

A greenhouse would be nice to have one day to extend the grow season.

 

[waveguide]

southern arizona here,

haven't grown a lot across the summer span, but done several outdoor spring grows, going to get stuff out this w/e with the weather now for flowering. someone said "mid march" and having done so several times, find it reliable.

that's not your question. i have an unfortunately vague memory that some year i have seen plants starting to flower going out significantly later than i expected which must mean sometime in may, definately later than i thought. i'd wait past 4/20 at least without using supplemental lighting. end of may to be safe. might find worthwhile discussion in the AZ state forum.

had some pondos i ran through the summer once, but last year, just before an extremely wet monsoon season, we had a string of four evil days in june where the sky was red and dark, with 30+ mph winds, rated 112f but reporting at 116f at 6pm. some of my plants did seem to survive the amount of exposure they got but they were all dead within two more weeks. summer 2021 sucked and i'm still fucking paying for weed. so watch the fuck out for those kind of days.

 

[f-e]

Do you have a good supply of water. Like a garden tap ?

 

[LiveFreeOrDie]

First off, thank you all for the wealth of information in this thread. You guys have given me a wealth of knowledge and a lot of areas to research further I hadn't yet considered.

Creeperpark I appreciate the information. Fortunately this is not a guerilla grow, so I should be able to keep a close eye on it. As for the strains, anything you might recommend as an alternative for this climate? I will likely try applying your advice next season.

waveguide Your climate seems to be the most similar to mine. Any advice for surviving the moonsoon season during a summer grow? Is it as simple as keeping the plants grounded and not too wet during flowering? I'm thinking I need a backup plan to cover/protect. As for flowering in the spring, if I had an indoor plant, I could move it outdoors this month for and finish flowering end of may? I have an indoor grow as well, might bring a plant out to test a spring flowering.

I do have a garden tap water supply. I'll keep an eye on PH and treat as needed.

For now I'm working on my soil design. I'm going to follow the advice earlier in this thread and try to make my own version of a super soil. I priced my soil locally, and I have the following choices for a base soil: Kellogg All Nature Garden Soil (For Flowers & Vegatables - Organic), Kellogg Raised Bed & Potting Mix (Organic - Plus), or another generic local top soil. All are a bout $8-$12/2.5 cu ft. Any tips on choosing the base soil? As of now I'll be following the soil mix in the video above, using a base soil, dolamitic lime, bonemeal, muriate of potash, kelp meal, and vermiculite. Open to suggestions on modification.

I haven't definitively decided on my grow containers. I'll either be using three 4'x4'x1.75' crates or five 100gal above-ground pots. This works out to 22.916 cubic teet per crate container (about 10 bags of soil each).

 

[TychoMonolyth]

You have water? Damn. Get one of these.
Orbit 58910 2-Outlet Programmable Hose Faucet Timer https://www.amazon.ca/dp/B008VDULGG/ref=cm_sw_r_apan_glt_i_CMT0ATP74KGFW7MQ9RTE?_encoding=UTF8&psc=1

 

[Three Berries]

In my area planting outdoors before June 10th can be risky. It's tempting when the end of May can be
nice and warm. But early June tends to bring in one last cold snap and that's where things go wrong.

A greenhouse would be nice to have one day to extend the grow season.

I have one of those garden greenhouse using pipes and plastic sheeting. About all it's good for extending the seasons early and late. But it's easy to set up and portable.

 

[troutman]

^^^ Do it and enjoy a longer growing season.

 

[VenerableHippie]

Mulch heavy around the plants to hold moisture. Another thing, if I grew in a very hot place like you plan on to I would
place a shallow tray of sorts in the bottom of hole before filling it up so it could collect maybe 2 or 3 inches of water at
most. This would help a lot I think. Shading the pots if you grow in them will help keep the roots cooler.

I used to grow in a hot climate.

First thing is: The Learning is in The Doing!

In my experience Troutman is right about mulch and about a tray of water under pots. An 8 foot Sativa will use 2 gallons of water a day when it's hot. My trays used to hold 2 gallons. It doesn't matter how hot it gets if the plants can drink water.

No need for shade cloth. But insulate your pots!!!! There is el cheapo insulation around made of recycled glass.

Sativa are TOUGH! Just don't let them dry out.

Sunlight hours ... minimum of six to start. At the other end, frost won't hurt your plants.

Good luck, THINK for yourself!

 

[therevverend]

Cannabis is a plant well-adapted to hot dry days and cold nights, especially strains with Central Asian genetics. The Malawi x Panama is the only one you're growing from a humid area but they're equatorial strains adapted to heat. As long as you have plenty of water they should do great. The last few years strains from Baluchistan have become available, they might be the most drought and heat resistant plants in the world. They're landrace hashplants from the high desert region along the border between Pakistan and Afghanistan. 120 degrees F all summer long and hardly any water and only cow dung applied in spring for fertilizer. They can get huge, yield well, and are coated in resin. The growers are very knowledgeable, I've chatted with them a bit and they breed selectively. Only the strongest survive.

You might want to look into them for next year, they're available from quite a few sources, Indian Landrace Exchange has a nice selection and sells them through Ace Seeds.

https://www.aceseeds.org/en/brands/indian-landrace-exchange/balochistan4.html

https://www.indianlandraceexchange.com/geneticlibrary/purple-dashti/

https://www.theseedsource.com/product/purple-dashti-mix-new/

Shade and ground cover will be your friend. Digging a hole and putting your containers in it might be a good idea. Containers tend to trap a lot of heat and high root temperatures can be deadly. I'd open the bottom enough the plants can get their roots down into the soil beneath. The bigger the container the less frequently you'll have to water, you don't want to be stuck watering 3 or 4 times a day. I prefer to water in the early morning but in your situation watering in the early evening might be the best time. I'd experiment. Hosing the plants down as soon as the sun is off them and then a deep watering the next morning might work well. You don't want dark colors and have shade cloth available in case you need it.

One thing that's not as obvious is that high temperatures usually mean windy conditions. Having good support for your plants might be necessary. If a storm blows through there's a good chance your plants will be thrashed, keep up on the weather reports and be prepared. Knowing your local conditions and being prepared is critical in any garden, extreme conditions make it that much more important. First year is never easy, I hope you're able to share what you learn and what was successful and what wasn't.

 

[Three Berries]

One thing I've noticed with my tent and VPD, if it is near or just under 1.0 then there is hardly any water use. Small plants and water once a week maybe. I've been running the tent humidity at a VPD near 1.2 and goes through the water a lot faster. I also put a fan blowing on the top of the soil all the time. But if they aren't using water they aren't growing otherwise..

So I wonder if there are strains better suited to lower humidity levels you get indoor growing in the winter?

 

[exploziv]

Its not the vpd's fault. vpd around 1 kPa are great! and plants at that vpd should be flourishing if all other environment parameters are within limits.

 

[zaprjaques]

Is the Lebanese from ACE?
​​​​​​If yes it should be very suitable for extreme heat and drought. Thats what the breeder said.

 

[Three Berries]

Its not the vpd's fault. vpd around 1 kPa are great! and plants at that vpd should be flourishing if all other environment parameters are within limits.

My problem was low calcium. Like turning on a switch.

Setting the humidly control at 1.1-1.2 then apply a -2F leaf temperature offset brings the VPD back down to the 1.0 range FWIW.

All hail AC Infinity......

 

[exploziv]

I feel like most people's problems under led is related to Ca..