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How to Grow Sunflower Microgreens







12+ days (using grow lights)

3-4 days

stacked with weight

soak 6hrs min - 24hrs max


  • 3 Bootstrap Farmer microgreen trays

  • 2x trays without holes + 1x tray with holes​​

  • Grow medium​

  • we recommend loose coco coir​

  • Water & sprayer​

  • in the absence of a water source with spray nozzle, we recommend a pressure sprayer​

  • SowYummy Sunflower seeds

  • 1 portion per 1010 tray, or 2 portions per 1020 tray

  • Anti-fungal spray

  • 10-15 lb weight


A minimum of 6 hours and a recommended maximum of 24 hours before you intend to plant your Sunflower microgreens, soak the seeds in room temperature water to soften the husk and activate the seed. Sunflower seeds will float so to ensure complete submersion place a weight over the seeds.

PRO TIP Mesh nylon produce bags work well to contain the seeds, making it very easy to weigh them down to prevent them from floating.

While a 6 hour soak will do, in our experience soaking Sunflower seeds for 12-24 hours results in more even germination.

Before you're ready to plant, drain the seeds, rinse them well, and allow excess water to run off them ("drip dry"). Sow your seeds while they are still wet.


If using a medium other than loose coco coir, prepare it according to manufacturer's instructions.

Nest the tray with holes inside one tray without holes.

Pack the tray with coco coir about 3/4 full. We use approximately 2 1/2 litres of loose coco coir per 1020 tray or 1 1/4 litres per 1010 tray. If the tray is too full you too much light will get in during germination, if it's not full enough, air circulation will be impeded.

Be sure to distribute the coco coir as evenly as possible throughout the tray and into the sides and corners to ensure good water retention.

Gently press the second tray without holes over the top of the coco coir to even out the surface. You don't need to press too hard, we are not compressing it just smoothing it out. Don't worry about the minor channels created by the tray, these will smooth out during watering and don't affect germination or growth.


In a pinch you can use a spray bottle for this step, however, to ensure adequate saturation a spray bottle will be onerous.

Using your pressure sprayer set to medium/light intensity, spray over the grow medium in a zigzag pattern from edge to edge, starting at the top of the tray, slightly overlapping each stroke. We find that 1-2 passes over the tray are sufficient.

The medium needs to have enough water to sustain germination for about 3 days, but not be so wet that fungus will grow or that young shoots start to rot while in germination. Think damp not soggy.

To check if your medium is adequately saturated, make a small hole in a corner of the tray with your finger. The coco coir should be wet all the way through but not dripping into the bottom tray.

PRO TIP If you're working indoors and are concerned about water on floors or other surfaces, place your tray inside an adequately sized storage bin to contain the overspray.


Using your hand, spread seeds as evenly as possible all over the grow medium. We like to start around the perimeter, then filling the rest of the tray.

Sunflower is sown quite densely, but try to avoid clumping as that promotes mold and damping off.

Give the seeds a light misting of the anti-fungal solution to help prevent mold.


Stack the second tray without holes ​in a nesting position over the sown seeds. Between 10-15 lbs is ideal. We use 15 lb sandbags.

Place the tray in a cozy area where it can stay undisturbed for a few days. A temperature between 18 and 20 degrees Celsius (68 Fahrenheit) is needed for healthy and even germination.

PRO TIP If heating your space is not an option, you can use a seedling heat mat under your tray.

Optionally to help prevent mold growth: every day during germination while the Sunflower is under weight, remove the weight and top tray, and mist with the anti-fungal solution.

PRO TIP When calculating germination/grow cycle days, we consider the day you planted your seeds as day 0.


On Day 4 your Sunflower is ready for light. We don't recommend leaving Sunflower in germination for longer as it is prone to damping off and mould. For this same reason we don't recommend putting Sunflower into blackout.

Your Sunflower shoots will be very small, pale, and bent over with the husks likely even touching the grow medium. Over the next couple of days they will straighten out and begin to photosynthesize.

On the first day under light give your microgreens another misting with the anti-fungal solution, and a generous bottom watering, almost a cup.

To bottom water, lift only the tray with holes and pour water into the bottom tray without holes, then lower the tray with holes. The grow medium and microgreens will absorb the water through capillary action.


You can grow your microgreens using other light sources but we recommend using complete spectrum LED grow lights.

Give your plants 16-18 hours of light every day.

PRO TIP Even plants need to sleep so if the space where you are growing your microgreens is exposed to sunlight, schedule the time your lights are off to coincide with nighttime.

Make sure you have adequate air circulation in the space where you are growing your microgreens as it is vital to the health of your crops. Sunflower especially likes good air flow and ventilation.

Water your microgreens daily. Sunflower tends to be thirstier than other varieties, we like to water it a little more generously than other micro greens, while being mindful not to overwater.

Sunflower husks are not edible and can be stubborn. To help them pop off the shoots, mist the canopy lightly with water. This will keep the husks soft and aid in their removal.

Starting on the 3rd day under light, after watering and misting, run your hand gently over the surface of the canopy in sweeping motions. Sweep your hand over the tops of the Sunflower gently, from side to side, top to bottom, and in circles. This will help dislodge loose husks. Starting this process too early however, increases your risk of damaging young shoots, and accidentally pulling them out of the grow medium.

PRO TIP With and without your assistance. Sunflower husks will pop off the plants and land on whatever is below them. Sunflower husks are known to be allelopathic which means that they release a substance which may inhibit the germination and/or growth of other plants. If you are growing vertically, place your Sunflower trays on the bottom most shelf so husks can land on the floor.


We prefer to harvest Sunflower microgreens at the cotyledon stage, at about 12-14, before the true leaf develops, or just after they start to peek out. In our experience Sunflower tends to become bitter as the true leaves grow. True leaves also have a furry texture that can be unpleasant on the palate.

If you intended to store the harvested microgreens, make sure the canopy and stems are dry. Microgreens stored when wet will start to decompose quickly.

The best way to harvest any microgreens is using a clean and sharp knife.

Scissors can work fine if you are harvesting to serve, however, if you intend to store harvested greens, scissors are not recommended. This is because scissors tear the stem rather than cut it, and torn stems bruise and start to decompose much quicker than stems cut cleanly with a disinfected knife.

We disinfect our knives using a solution composed of 1 part 3% food grade hydrogen peroxide mixed with 2 parts filtered water.

To harvest Sunflower microgreens, using one hand gently grab hold of a modest handful of the greens and slice the knife blade across the stems a little above the substrate to avoid picking up grow medium.

PRO TIP If some husks were late to fall off, or didn't fall off at all and you pulled them off, all or some of the cotyledon underneath will be yellow because it didn't have a chance to photosynthesize. Yellow Sunflower microgreens are perfectly safe and delicious to eat. If however they are "burned" - black or brown - dispose of them as they will decompose quickly.

Store any microgreens in a clean airtight container in the fridge. If you are going to wash them, do so only when you intend to use them.

In our experience healthy, properly harvested and stored microgreens will keep in the fridge for at least 10 days.

Happy eating!

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