Late April is decision time for outdoor cultivators. Your clones or seedlings have been vegging under lights, your field prep should be wrapping up, and the window for getting plants in the ground is opening fast. Mess this transition up and you'll pay for it all season.

I've transplanted across 1,200+ acres of outdoor hemp and cannabis over the years — from Colorado to Paraguay. The fundamentals don't change with scale. Here's how to handle the next two weeks.

The Hardening Off Window

If your plants have been in a controlled indoor or greenhouse environment, you cannot throw them straight into the field. I've watched operators lose 15-20% of their transplant stock because they skipped hardening off or rushed it. That's thousands of dollars in genetics, labor, and time.

The process takes 7-10 days. Here's the sequence:

Days 1-3

Move plants outside for 2-3 hours in the morning. Morning sun is gentler — you want indirect or filtered light. Bring them back inside before afternoon intensity peaks. Keep them sheltered from wind.

Days 4-6

Extend outdoor exposure to 5-6 hours. Introduce some direct sun but avoid the 12-2pm window if temps are above 80°F. Start leaving them in light wind to strengthen stems.

Days 7-10

Full day exposure. Leave them outside overnight if nighttime temps are consistently above 50°F. If you're seeing temps dip below that, wait. Cold shock on unhardened transplants causes stunting that takes weeks to recover from — weeks you don't have in a single-season outdoor grow.

Nighttime Temperature Thresholds

This is where I see the most mistakes at commercial scale. Growers get excited about warm daytime temps and rush transplants out. But cannabis is sensitive to root zone temperature, especially in the first two weeks after transplant.

The hard rule: don't transplant until nighttime soil temps (not air temps — soil temps at 4-inch depth) are consistently above 55°F. I carry a soil thermometer to every field site. Cost is $15. The information it gives you is worth thousands.

If you're in zones where late frost is still possible — parts of the Northeast, Upper Midwest, mountain West — you're probably two to three weeks out from safe transplant. Use this time to finish hardening off and finalize your field layout.

Site Prep Checklist

By now your field should be nearly ready. If it's not, here's what needs to happen this week:

Soil Testing

If you haven't pulled soil samples yet, do it now. You need pH (target 6.0-7.0 for cannabis), NPK levels, and micronutrient profile. Amending soil takes time to integrate — you want at least two weeks between amendment application and transplant.

Irrigation Verification

Run your drip lines or pivot system end to end. Check for leaks, clogs, and pressure consistency. I've seen operations lose a full week of early growth because they discovered irrigation problems after transplant. Finding out your drip tape has rodent damage when you've got 10,000 plants in the ground is not where you want to be.

Weed Management

Lay your ground cover or mulch now. For commercial scale, we use landscape fabric with pre-cut holes at planting density. This isn't optional at scale — hand weeding 50+ acres is a labor cost that will eat your margins alive. If you're running no-till or cover crop systems, mow and crimp your cover crop at least two weeks before transplant to give it time to mat down.

Spacing and Density

Final call on plant spacing needs to happen before transplant. For most outdoor cannabis and hemp cultivars, 5-6 foot spacing between plants and 6-8 foot row spacing is the sweet spot for airflow and canopy management. Tighter spacing means more plants per acre but dramatically increases humidity in the canopy later in the season — and that means mold pressure.

Genetics Selection Is Locked

If you're still debating genetics at this point, you're behind. Your variety selection should have been finalized in February or March. But if you're making last-minute adjustments, prioritize:

Mold resistance over THC/cannabinoid potency for any outdoor operation in a humid climate. A variety that tests at 22% THC but fails mold testing at harvest is worth zero.

Flowering time matched to your latitude. If you're above the 40th parallel, you need varieties that finish by mid-October at the latest. Late-finishing sativas are a gamble north of that line — one early frost and you're done.

Proven performance in your microclimate. Trialing new genetics is fine on 5% of your acreage. Don't bet the farm on a variety you haven't run in your specific conditions.

The Next Two Weeks

Your transplant window is coming up fast. Use this week to finish hardening off, verify your field infrastructure, and confirm your labor plan for transplant day. At commercial scale, transplanting is an all-hands event — make sure your crew is scheduled, trained, and equipped.

The decisions you make in the next 14 days set the trajectory for your entire season. Don't rush it. Get it right.