How to Store Canna Lily Seeds for Successful Germination

Canna lilies also known as Indian shot are beautiful tropical and subtropical plants that produce colorful flowers in shades of red, orange, pink and yellow. Their large, lush leaves also make a striking statement in flower beds and gardens.

While canna lilies are often grown from rhizomes or tubers, you can also propagate new plants from seeds. However, canna lily seeds have a tough outer coating and need special treatment in order to germinate successfully. This article provides tips on collecting, storing and pretreating canna seeds to get the best germination rates.

When to Harvest Canna Lily Seeds

Canna lilies produce seed pods that turn brown or black when ripe. The pods will split open when fully mature, releasing shiny black seeds

The best time to harvest canna seeds is after the seed pod has naturally opened You’ll get the highest viability if you collect the ripe seeds as soon as possible after the pods split.

Watch the seed pods closely so you don’t miss the optimal harvest time. The viable seeds will be black or very dark brown in color. Any white or lighter seeds are likely immature and won’t sprout well.

Use scissors or pruning shears to cut off the dried seed heads. Place the cut pods in a paper bag or envelope and store in a cool, dry spot while you finish harvesting. This prevents seeds from accidentally spilling out.

Once you’ve gathered all the seed pods, break them open over a bowl or tray to collect the seeds. Pick out any bits of pod material, leaving only the black canna seeds behind.

Storing Canna Seeds for Later Planting

Fresh canna seeds have a short viability window of just a few months. For best results, start the germination process as soon as possible after gathering the seeds.

However, you can store canna lily seeds in the fridge to buy yourself more time if needed. Place the dry seeds in an airtight container and store in the refrigerator. Kept at 35-40°F, canna seeds may remain viable for up to a year.

For longer storage, consider freezing the seeds. First, package seeds in an airtight, moisture-proof container like a ziplock bag or glass jar. Remove as much air as possible from the container before sealing. Place in the freezer, where canna lily seeds can potentially stay viable for 2-3 years if kept below 0°F.

Label containers with the seed type and year collected before freezing. This helps you keep track of inventory.

Pretreating Canna Seeds Before Planting

Canna seeds have extremely hard outer coatings that must be weakened for the seed embryo to imbibe water and begin germinating. There are a couple methods you can use to pretreat seeds prior to planting.

Scarification

Scarification is the process of intentionally damaging or abrading the seed coat to allow moisture penetration. For canna lily seeds, a light sanding is an easy and effective scarification technique.

Simply place seeds on a sheet of medium grit sandpaper. Gently rub the seeds back and forth to lightly scuff and scratch the surface of the coatings. Don’t overdo it – the seed embryo itself is very fragile. The goal is just to rough up the outer shell enough to allow water uptake.

After sanding, rinse the scarified seeds under running water while rubbing gently between your fingers. This washes away any coarse debris and further permeates the abraded seed coatings.

Hot Water Soak

You can also pretreat canna seeds using hot water to soften the impenetrable coatings.

Bring water to a boil, then take it off the heat. Place the canna lily seeds in a bowl and pour the hot water over them. Let the seeds soak in the hot water bath for 12-24 hours.

Drain off the water and rinse the seeds. The warm water soak will have softened the seed coatings so they can begin to absorb moisture and germinate when planted.

Breaking Dormancy With Cold Stratification

Some species of canna seeds have an inherent dormancy that requires exposure to cold temperatures before germination will occur. This process mimics the winter conditions seeds would experience naturally before sprouting in spring.

To cold stratify canna lily seeds:

• Soak seeds in room temperature water overnight. This begins to hydrate the seed embryos.

• Drain excess water and seal seeds in a ziplock bag with a lightly moistened paper towel. Remove as much air as possible.

• Place the bagged seeds in the refrigerator for 4 to 8 weeks. Check periodically and remoisten the paper towel if needed.

• After cold stratification, remove seeds and rinse before planting. The moist chilling period will have helped break natural dormancy.

How to Plant Pretreated Canna Seeds

Once you’ve scarified, soaked in hot water, and/or cold stratified the canna lily seeds, they are ready for planting. Here are a few tips for getting pretreated seeds off to a great start:

• Plant seeds shallowly, no more than 1⁄4 to 1⁄2 inch deep in pots or trays. Cover lightly with seed starting mix or vermiculite.

• Keep the planting medium consistently moist but not saturated. Use a spray bottle to mist often.

• Provide bottom heat of 70-75°F to encourage sprouting. You can set pots on heating mats or germination trays.

• Cover trays or pots with plastic domes or wrap in plastic to maintain humidity levels. Remove any condensation daily.

• Germination should occur within 1-4 weeks. Remove covers once seedlings emerge.

• Transplant young canna lily plants to the garden after all danger of frost once they reach 6 inches tall.

With proper harvesting, storage, pretreatment and planting, you can successfully grow beautiful new canna lily plants from seeds. Paying attention to their unique seed starting requirements will result in higher germination rates. It’s well worth the extra effort to propagate gorgeous cannas that will thrive in your garden for years to come.

Frequently Asked Questions About Storing and Germinating Canna Lily Seeds

Many gardeners new to growing cannas from seed have questions about the best practices. Here are answers to some of the most common inquiries:

How long are canna lily seeds viable after harvesting?

Fresh canna seeds will remain viable for 2-3 months if properly stored in a cool, dry place. For longer storage, refrigerating extends viability up to 1 year, while freezing may allow seeds to last for 2-3 years if kept below 0°F.

Do you have to start canna seeds indoors?

Yes, it is best to start canna lily seeds indoors or in a greenhouse. They require warm soil temperatures and high humidity to sprout, which is difficult to maintain outdoors. Once sprouted and established, young seedlings can be transplanted into the garden.

What type of seed starting mix should be used?

Canna seeds do best in a lightweight, fast-draining mix. Avoid heavy, dense soils that may inhibit germination. A good option is a general purpose seed starting mix composed of peat moss, perlite and vermiculite.

How deep should you plant canna lily seeds?

Plant canna seeds very shallow, no more than 1⁄4 to 1⁄2 inch deep. They require light to germinate. If planted too deep, the emerging seedlings may not be able to break through the soil surface.

How much water do canna seedlings need?

Keep the starting medium consistently moist but not waterlogged. Heavy saturation can cause fungal issues. Use a spray bottle to frequently mist the soil to maintain adequate moisture levels. Allow pots to partially dry out between waterings.

When can you transplant canna lily seedlings?

Canna seedlings can be moved to the garden after the last spring frost once they have 4-6 mature leaves and are 6 inches tall. Harden off plants for 7-10 days before transplanting into the ground outside.

How far apart should you space canna lily plants?

In the garden, allow 24-36 inches between plants to accommodate the large foliage and spreading rhizomes. Cannas are tropical bulbs that need adequate space to reach full size and flower well.