Herb Grow Guide

Updated October 14, 2026

Grow herbs in your Flex Farm with the light on 18 hours a day, the pump on 24/7, a target pH of 6.0, and nutrients at base + 700. Plants are ready for their first harvest about 6 to 8 weeks after transplanting.

Refer to the instructions found in the Flex Farm Grow Guide to set up your Flex Farm to grow herbs. You will use the same methods to check and adjust pH and nutrient levels. You will also need to set the light timer as directed in the Guide.

Click HERE to purchase our Classic Herb Seed Bundle and Warm Herb Seed Bundle.

Quick Start Reminders

Light Timer: Leave ON continuously for 18 hours per day (16 hours minimum)
Water Pump: Leave ON 24/7
Target pH: 6.0
Target Nutrients: Base reading + 700 = target number

Planting Seeds

Thoroughly wash your hands with soap and water.
Locate your rockwool flats, nursery tray, and seeds.
By gently bending the rockwool flat, remove the number of cubes that you will not be planting.
Each flat has 200 cubes.
Place the rockwool flat with the planting hole side up into the provided nursery tray.
Completely saturate the rockwool using cold water and let it sit for at least 5 minutes.
Do not use hot water.
Without squeezing the rockwool, pour out any excess water.
To plant, place four unpelleted seeds per hole in the rockwool.
For pelleted seeds, place only one seed per hole.
Cover your nursery tray with a clear covering (such as a plastic food storage bag, cling wrap or a humidity dome) and place it in the warmest area in your space.
Seeds do not need light to sprout.

Note: For herbs, you can plant every plant space in your Flex Farm. It is not necessary to plant in a grid pattern.

Germination

Herb seeds on average take 5-7 days to germinate. Some may take longer due to the variety or age of the seeds.
Fill a clean spray bottle with plain water, and spray your planted seeds 1-2 times daily until they sprout.
Remove the plastic covering once your seeds sprout.
For full germination instructions, refer to the Flex Farm Grow Guide Germination section.

Note: Rosemary takes longer to germinate and has a lower germination rate than the rest of the seeds.

Transplanting

You can transplant your seedlings when they have sprouted above the rockwool seed hole.
This will help prevent them from being pinched off during transplant.
Leave seedlings to grow in the nursery tray another day or two to mature if not sprouted above the rockwool.
Herbs can be planted every plant spot in the Flex Farm.
For taller herbs, such as chives and basil, we recommend planting the top panels in the Flex Farm.
For full transplanting instructions, refer to the Flex Farm Grow Guide Transplanting section.

Note: For rosemary, let seedlings grow longer in the germination tray until they reach a height of 1 inch.

Harvesting & Maintenance

Once the seedlings are transplanted into the Flex Farm, it will take about 6-8 weeks before they are ready for the first harvest.
Mature plants can be harvested weekly, bi-weekly or when necessary.
Herbs such as cilantro and parsley might require more frequent harvesting to allow room for regrowth.
If properly cared for, herbs can remain in the Flex Farm and be continuously harvested up to four months before replanting.
Refer to the instructions in the Flex Farm Grow Guide for cleaning recommendations and weekly maintenance.

Food Safety Protocol

It is important to follow proper food safety protocols when harvesting plants.
Before doing anything, thoroughly wash your hands with soap and water and apply food safety gloves.
Clean your tools.
Make sure any bins being used for storing or transporting harvested plants have been sanitized.
Wash any surfaces you plan to use during the harvest.
Access Farmative to view and download Food Safety resources.

Caution: You must cut back the roots of plants located in the back root chambers above the tank tubing if they have been growing in the Flex Farm for longer than 8 weeks. The roots will grow into the vinyl tubing and obstruct the water flow.

Harvest Method Guide

Herb variety	Harvest method
Genovese & Sweet Thai Basil	Wait until at least 6 inches in height, trim right above a node (pair of leaves) to promote bushier growth.
Chives	Wait until at least 6 inches in height, trim starting with the largest stems within 1 inch of the rockwool.
Cilantro	Wait until at least 6 inches in height, trim the top 1/3rd of the plant, leaving 2/3rd of the plant to feed itself. If the plants start becoming crowded, take cuttings from the bottom of the stems to thin out.
Dill	Wait until at least 6 inches in height, only trim the outer, largest leaves. Trim where the stems of the leaves meet the main stem.
Oregano	Wait until 6 inches in height, trim the top 1/3rd of the plant, leave from leaves for the plant to feed itself. If the plants start becoming crowded, take cuttings from the bottom of the stems to thin out.
Parsley	Wait until at least 6 inches in height, trim starting with the largest stems within 1 inch of the rockwool.
Rosemary	Rosemary will not reach full maturity for 2-3 months. You'll be able to pinch tops off to promote growth in the first month and use those, but they will not be heavy producers until the plant is mature.
Sage	Wait until 6 inches in height, trim above a node (pair of leaves) to promote bushier growth.
Thyme	Wait until 6 inches in height, trim the top 1/3 of the plant, leave from leaves for the plant to feed itself. If the plants start becoming crowded, take cuttings from the bottom of the stems to thin out.

Harvested Herb Storage

Herb variety	Storage tips
Genovese & Sweet Thai Basil / Chives, Rosemary, Sage, & Thyme	Do not store at a temperature less than 50°F (10°C). Pick the leaves off the stems and lay them in a single layer in paper towels or a clean kitchen towel, roll them and store in a container. Alternatively, leave stems on and place in a glass jar or container with water. Wash before use. Wrap loosely in plastic wrap and store them in the refrigerator crisper drawer. Alternatively, wrap them in a damp paper towel and store them in a plastic bag or airtight container. Wash before use.
Cilantro, Oregano, & Parsley	Wrap them in a damp paper towel and store them in a plastic bag or airtight container within a refrigerator crisper drawer. Alternatively, leave stems on and place in a glass jar or container with water. You can add a plastic bag over top to contain humidity. Wash before use.
Dill	Wash in cold water, remove excess moisture with a salad spinner, and wrap the bundle in several damp paper towels. Place the wrapped stems and leaves in a plastic bag or airtight container. Store in the refrigerator crisper drawer.