Magic Pods: When to gather Pacifica Iris seeds

October 2018, Kathleen Sayce

When I first started growing Pacifica Iris from seed, I collected several pods too early. The seeds were not fully developed, and resulting germination rates were low. There were also the usual vole, jay and squirrel problems—these animals being all too willing to eat germinating seeds. 

Ripe PCI pod, tips just starting to spread. It's time to gather fresh iris seeds. Photo by Bob Sussman

Come forward a few years; this year I was late gathering seeds, due to trips, work, and other commitments. What seeds I did collect were heavily colonized by fungi, despite a dry long summer along the Pacific Northwest coast. About half the seeds were composted due to fungal coatings. In many pods the seeds were completely felted together with fungal filaments. 

All of this left me with a complex about the right time to gather ripe Iris seeds. I asked for advice among a number of SPCNI members, thinking I must not be the only person who has struggled with ripening, predation, and fungi, and several people responded with comments and photos, including Debby Cole and Bob Sussman. I thank both of them for their helpful notes, and Bob for taking time to send photos. 

Label wrapping a pod that is close to being ready. Photo by Bob Sussman.

Timing of seed ripening is based on tracking pod appearance. Pods go from skinny green to plump yellow and then brown. Six to seven weeks is the usual incubation period after flowering. Species often ripen quickly, including Iris tenax, I. innominata and I. thompsonii, which all may have yellowing and opening pods in five to six weeks in warm climates. 

A slight opening of the pod tips may appear when seeds are ripe. This varies from ‘never opens the slightest’ to ‘splits wide open and tosses seeds out’. The latter usually happens when I’ve been inundated with visitors, trips or work and do not have time to gather pods. Organza bags can help contain the seeds, but don’t leave them for weeks, or the bags will be chewed through and the seeds removed. 

Open pods, some seeds have already shed. Note the withered flower, still attached, lower left. Photo by Bob Sussman.

The corollary to ‘never opens in the slightest’ is that those pods may need to be cut open to free the seeds inside. Some Iris douglasiana pods have this character. They go from green to yellow, often with a ‘shrink-wrapped over the seeds’ look, and then to plump brown, by which time the pods are woody, hard, and require tools to open without shedding blood. The worst of this lot are also the last to flower and thus to ripen seeds each summer. 

When ripe seeds are left too long, they will be discovered by voles, crows, jays, and various molluscan and insect seed-eaters. The only solution is to get to those pods ahead of the seed-eaters. 

Fungi appear to grow in the pod tissue and seed coats, and not in the seeds. I’ve had healthy seedlings grow from seeds heavily covered in fungi. But we can't seen around seeds that have visible mold. Biosecurity is getting tighter all the time. If we gather seeds at the right time, and reduce/eliminate fungi thereby, this helps reduce the chances that seeds will be rejected by inspectors. 

Viable fresh seeds, just released from the pod, which is still green. These seeds will dry to dark brown. Photo by Bob Sussman. Note the absence of fungi on these seeds. 

As for color, that is a feature of the moisture content of the seed. Fresh, viable seeds are very light brown, and dry seeds are dark brown. 

When Pacifica Iris Pods Are Ripe

Kathleen Sayce

Mid to late summer is exciting:  it's harvest time for Pacifica Iris pods. Some species irises shed seed by early July in my garden, including Iris tenax and I. innominata. These species often grow at high elevations in the wild, flower in May or June, and have ripe seed by mid July to early August. They waste no time cranking out the next generation. Other species take more time to ripen seeds, nine weeks instead of five to six weeks, including I. douglasiana. Pods often go through a color change as they ripen, from green to gold or yellow. Even when not opened, a yellow pod has mature seeds inside, ready to collect. 

Just a few weeks ago, seed pods were green. 

Iris pods are opening all over the garden by late July, when the mesh bags come into use. Here, all pods in this cluster have opened, the tips are spread on the upper two, and the bottom one has valves spread to show the seeds inside.

Mesh bags or nylon stockings are good devices to use to contain seeds and ensure that a gardener's work in crossing specific parents isn’t lost at the seed collection step. Saving even a few seeds from a choice cross can be important in a hybridizing program. 

I cut the stems and collect the pods, still in their mesh bags, to dry before taking out the seeds. The stems can be tied together with a wire tie or string, hung in a dry shady place, out of the sun and away from direct heat––just as you would dry herbs or flowers, or put into paper bags in a warm dry spot. After a few days, any pods that can open, have done so, and the seeds are ready to clean and package. 

A basket of treasure:  Ripe pods in paper bags, ready to dry indoors. 

Normally the valves separate from the pods, and the seeds break off and scatter. Occasionally pods stay closed or only partially open. Either the tip will not separate, or the sutures along the edges do not open.  When this happens, I use a knife or razor blade in a holder to cut the tip off, or cut along a suture line, being very careful to keep my fingers intact, and to not cut into seeds. Then I gently peel out the seeds.

Seeds go into a bowl. Use a large bowl that you can swirl seeds around in. This lets you blow or toss seeds outside to separate seeds from chaff and pod fragments. I also use a sieve to shake out fine bits if the pods are dirty. I clean the seeds and remove all non-seed bits and pieces, insects, et cetera. Separating seeds from chaff is a very old process. Humans have been doing this for thousands of years. And it’s fun! 

After the seeds are clean, I put them in a clean bag (mesh or paper), to continue air drying. The label moves with them. I save seeds for seed exchanges, such as Society for Pacific Coast Native Iris, and Species Iris Group of North America.  

I learned the hard way to not put fresh seeds into glassine or plastic bags––they mold. The mold doesn’t kill the seeds, it’s just in the seed coats, but it looks terrible, and when it’s really bad, all the seeds are encased in a dense whitish mold into one solid lump. Ugh!  If there's too much mold I scrub the seeds with a plastic scrubby to clean them, then rinse and re-dry the seeds. 

Drying seeds, in a row of paper bags. This takes patience, and at least ten days!

Let the seeds dry thoroughly before packaging each seed lot. I’m not naturally a patient person, so this is hard. Wait ten days, at a minimum. More is better. Only when the seeds have dried indoors, in a clean mesh bag, and I have let the days slip past, do I then put the seeds into an envelope, label it, and set it aside to send to a seed exchange. I also share seeds out to gardening friends, and this is when those seeds are mailed. 

Labels need to include what, when, where, and any details of the plant or flower that are important. List:  Pod parent, pollen parent if known, the flower color on the pod parent if it’s a species or unregistered new flower, likewise any characteristics of the pollen parent that were important to note, or bee-pollinated, if open pollination was used. If you use crossing codes to track garden crosses, write down those codes too. This helps you and others track the parentage of your seeds. 

Another task is to take all the used mesh bags, wash them in warm soapy water, rinse, dry, and then freeze them for at least two weeks. Why freeze the bags? If any invertebrate eggs are in the bags, this will kill them. Washing, drying and freezing helps ensure that the bags are clean, and ready to use again next year.  

Do you grow PCIs, and do you save seeds to give to other gardeners?

Bagging Pods to Save Pacifica Iris Seeds

Kathleen Sayce

All irises have pods with three valves that open and spread when seeds are mature and pods are dry. Open pods toss seeds a few feet, shaking seeds out in the wind and opening a bit more from day to day. Iris pods often open at inconvenient times, usually on hot sunny days when I'm away from home. This was a frustrating reality for me when I started crossing plants and saving seeds, because I'm often hiking in mid summer, away in the hills when those pods pop open. 

I. douglasiana has green pods with three valves. Bag and save upright pods, not the sprawling stems. You will find the mature pods more easily later if they are upright.

I began collecting iris seed by designating small paper bags for each variety, adding pods to the bags day by day and week by week, cutting off the pods when the color started to change from green to brown. But inevitably, some slip past, and open on their own. Tracking seeds of choice hybrids was tough:  several times the pod opened and seeds slipped out, and were scattered in the garden in less than 24 hours. When you’ve hand pollinated the flowers after growing the parent plants, losing the seeds at ripe pod stage is tough. 

Iris douglasiana has the longest ripening period. Pods may take nine weeks to fully mature.

Iris douglasiana is the most widely grown Pacifica Iris, and its pods are ripe about nine weeks after flowering. Some species ripen a bit earlier, like Iris innominata, which has lovely yellow flowers; in five to six weeks the seeds are mature and ready to gather from this species. I learned this the hard way, going out weeks too late to bag what I thought were green pods and finding only the pod sections, brown, dry and open with the seeds long gone. 

Iris innominata can ripen seeds in five to six weeks. I know, because I lost all the seeds the first year this species flowered in my garden. I sauntered out in week six to put pod bags on the three green pods, only to find they were brown, open, and the seeds were scattered. 

There is a solution:  organza party bags, AKA seed pod bags. These days I check plants a few weeks after flowering, cut off flower stems on plants whose seeds I do not plan to save, and put mesh bags over the rest. For my original purchase, I got green bags, thinking green would blend in better over the summer. Not bad, but I now find bags all winter, even in spring, that were overlooked the prior summer! 

Mesh bag on green pod––unobtrusive, discrete, and could be easily overlooked in a few weeks when the seeds are ripe. 

When the pods are ripe, I cut the stems off, tie them together, label the bunch, and dry the pods still in the bags. If they open and shed seed, great, this saves me time prying open each pod. If they don't––and some late flowering I. douglasiana plants often do not open their pods––I slice each pod open along one side and pry out the seeds.  

If the seeds are going to a seed exchange, they go back into a clean mesh bag, labeled, and air dry for a couple of weeks. If I keep seeds to plant, I plant them immediately outside. 

The goal:  New seedlings. Note the styrofoam boxes, top layer of chicken grit, and mesh cover. The grit helps in heavy rain to keep the soil mix in place. The mesh wards off any number of animals and birds that think germinating Pacifica Iris seeds are tasty snacks. These seedlings will go out into the ground in early fall. 

I live in a summer dry, winter wet climate, which Pacifica Iris prefer. Seeds go into styrofoam boxes, in a well drained mix, covered with a thin layer of fine granite gravel (chicken scratch). A fine wire mesh cover goes over the top, to keep voles, chipmunks, jays, crows and other animals from eating germinating seeds. The seed boxes stay outside all winter, no matter the weather, and in the spring the next crop of Pacifica Iris seedlings emerge. 

I'd like to know what other iris growers think of using mesh bags, and what color of bag you recommend. I need to order more. I’m thinking red or orange for the next order. Or should I go wild and order mesh bags to match the pod parent flowers?