The Biarums of Spring

Springtime! The curious odor of some small rotting thing wafts up from a potted plant, and I know I missed a Biarum flower bud until it opened!

The above species is Biarum rhopalospadix K.Koch from Southern Greece. Our plants were purchased some time ago from Rare Plants in the UK (which has been an excellent source of high quality Biarum species for us).

This genus of dwarf cormous Aroids (relatives of the Calla Lily) can be found all around the Mediterranean Sea and thence along the region of Winter-wet Summer-dry weather stretching out through Iran and even further East. Most of the species that are commonly grown flower in the late Fall before the leaves emerge - called "hysteranthous" flowering. However, there are quite a few that flower in the Spring, as the leaves are drying down in preparation for their Summer dormant period (keep them in the shade and dry all Summer or they are at risk of rotting).

Another species that is now starting to flower is Biarum tenuifolium ssp. zelebouri (also known as Biarum zelebouri). The buds are amazing to watch as they push out of the ground over a week or two (depending on the weather).

Actually, for our growing conditions in coastal California, the entire Biarum tenuifolium group tend to be Spring flowering. The Biarum tenuifolium ssp. galianii below is almost ready to open. In the wild, they come from Southern Spain.

This is not just the time for the wonderous small flowers of the genus - if you hand pollinated any of your flowers (or if you get really lucky with help from the local insects) you may get seeds pushing up through the ground just now. I have been unable to find many (virtually any) images of fresh Biarum seed heads as they emerge from the ground - and admittedly after five years of growing Biarums, this is the first seed head we have had actually reach maturity and get pushed up to ground level!

Above is a photo of an emerging ripe seed head of Biarum dispar at our farm. A first for us!

We grow our Biarums in deep tree seedling pots so they have lots of room for root growth. We buy out pots from Stuewe and Sons in Oregon https://stuewe.com/, generally using the TP38 pots (3" square pots that are 8" deep!). These do not stand on their own, so we use their heavy trays MT38TI to keep the pots upright. Each tray holds 20 and we find them invaluable for organization and keeping all the plants healthy. We plant in a mixture of 2 parts Pearlite to 1 part general cactus potting soil, with added bone meal:

Keep the plants in light shade (30 shade cloth or under an open-branched tree for us). We are finishing letting the pots dry out for their Summer rest now at the end of April. We will resume watering around Hallowen usually. The Pacific Bulb Society has a wiki on Biarum if you'd like to look at some other species.

If you want to try growing these yourself, here are the three sources we have found ethical and reliable sources of quality plants (these are NOT affiliate links, we just buy our plants generally from these folks):

Illahe Rare Plants (USA): https://www.illaherareplants.com/

Rare Plants (UK): https://www.rareplants.co.uk/product-category/shop/biarum/

Seeds of Peace (IL): https://seedsofpeace.info/

Biarum can grow from seed to flowering in three years or so if you want to give starting from seeds a try. Seeds of Peace (above) is the only of the three sources that carries seeds. Happy Growing!

The Fall Daffodils

It is that season between Halloween and Thanksgiving, when so many of the bulbs that waited patiently over the summer sense the return of cooler temperatures and the promise of rain. They flower now, so the seeds can germinate in the early Winter and be large enough to survive the Summer when it arrives.

Narcissus serotinus

The first of these for me is Narcissus serotinus.

The flower is less than an inch across held on a six inch stem. It grows into clumps that flower profusely this time of year, at least when it likes the growing conditions. In the wild, it grows largely on the Atlantic coast of Spain and Portugal, with another population across Gibraltar in Morocco. There has been confusion with some of the other Fall flowering species, such as Narcissus obsoletus - in fact, this appears to have been a cryptic species complex rather than a single species until recent studies clarified the situation. The photo above is the "true" species. There are several sources online for seeds or bulbs - both should be ordered in the Summer or late Summer. The flowers come up and add a spot of fragrance and brightness to the cooling days! I grow them in pots that are 3" square and 8" deep - I order from Struewe and Sons in Oregon (not an affiliate link - I just buy from them https://stuewe.com/). See the Growing section further below. If you hand pollinate them, you are likely to get seeds that can be planted immediately (see growing section below). Capsules that are developing look like this (wedding band for scale is 7mm wide):

Narcissus viridiflorus

The famed Green Daffodil! It flowers a week or so after Narcissus serotinus for me, in the years it decides to flower. Some years all the mature bulbs flower, some years none of them, and some years it is more mixed. I haven't figured out the pattern and how it relates to the weather.

The plants are short, perhaps to 8" tall. They tend to put up a leaf or a flower stalk - the two look almost identical at first. The flowers are fragrant, almost to an extreme, in a manner that reminds me of the much more common Paperwhite daffodils. If pollinated, they tend to set seeds, though in my experience they need pollination assistance. I use a tiny paintbrush, and work the bristles very gently into the tube of the flower. Then, repeat with the next flower, and so on.

Narcissus miniatus

These are in the middle of a taxonomic controversy. I side with Dr. Koopowitz that this is a very morphologically distinct plant. That said, you will encounter folks that believe this is a synonym of N. obsoletus (the name of that taxon references its lack of a floral cup... this plant clearly has one). It is a delightful tiny plant, one of the smallest of the daffodils. The discussion and original description as a species is here.

Growing

These plants are from Mediterranean climates - climates that are warm and dry in Summer, cool (not really cold - frost, not heavy freezes and snow) and moist in the late Fall through Spring. That means they grow well in similar places, such as around the Mediterranean, coastal California, the Cape of South Africa, and places with similar climates. In other places, they are going to need a bit more support.

Pots

These benefit from deep pots. They don't need a lot of side-to-side space, so a 3" square pot is fine - especially if it is 8" deep or so. Pots used for forestry seedlings seem to be the most readily available that are deep and narrow (and reasonably priced and durable). The problem with these sorts of pots is that they don't make great retail sales pots, as they tend to fall over if not supported in a socketed tray. Think of the trays and the pots as a coupled and necessary system. I use the 3x8 apple tree pots and the 20 socket trays (not an affiliate link).

Trays and Sun Protection of Pots

Pots can overheat in the sun very, very quickly. This can kill roots and stunt growth or even kill the plants. I've had pots in the sun more than 50 degrees Fahrenheit hotter than the air. That means that the sides of the pots should be protected from direct sun. If they are packed into trays, the pots protect each other, except at the edges of the trays. In these locations I cut strips of bender board (used for edging lawn areas) and clip them to the pots - see the brown strips held on with clothespins in the photo below.

Soil

I have gone from being a purist, making my own soil from purchased materials that are very clean an standardized, to a slightly more pragmatic person. The soil needs to never go sour (or anaerobic - it has to drain well and aerate well, which are different attributes). These days I tend to use a commercial cactus or palm tree soil, which I then use as 1 part cactus soil to 3 parts pearlite. I also tend to add bone meal and organic bulb food and mix it into the soil. I do use a small concrete mixer for ease (I can't seem to find the warranty paperwork for my back or my knees, so mixing by hand has beome less fun). The result is a very open soil that drains fast but retains some moisture.

Growing Area

These plants are usually found in the understory of shrubby hillsides. That means that they often have some shade, or filtering of the sunlight. They will definitely grow in full sun if the shrub cover is burned away or otherwise removed, however seedling establishment may be hindered (personal observation) during these periods until the shrubs or other plants provide some radiation protection of the bare ground. As such, I use an incomplete shade cloth cover if I not growing them under trees, such as in this setup. Provide protection for the midday and early afternoon sun, and allow direct sun in the mornings ideally, although it can work with some afternoon direct sun, especially if it is broken up into several relatively short periods of direct exposure.

Keep the pots and trays well above the ground. This prevents lateral movement of most pests and renders the pots harder to reach for many pests, such as slugs.

Irrigation

I use drip. Most of the time, it is about every 4 days for about 15 minutes in the early evening. Evening is best, as it gives a lot of time for water on the leaves to evaporate or be absorbed by morning. There is no drip tubing I've found that fits the pot spacing (3"), so I buy tubing with emitters every 6" and cut out 3" between emitters and rejoin the tubing. I make manifolds that fit a 4 pot by 5 pot tray. When bringing plants out of dormancy, water the pots once and then wait either several weeks before watering again, or until visible growth starts (there are exceptions - in some cases "dormant over summer" does not mean "dry over summer", and in some cases the first growth is a flower stalk that does not expect to be rained on until much later in the growing season, just for example). Once visible growth is underway, it is generally fine to go to an automated watering cycle.

Entering dormancy requires that most of these be dried out gradually - no baking in the California sun (those who recommend baking in the sun are often in cooler and/or more humid climates where things won't reliably dry out over a month of just being out in the shady air). I will remove watering by moving pots as needed out of the irrigated trays and into "going dormant" trays. These are often in the same light conditions, but unwatered or watered manually occasionally. Pick pots where there is yellowing of leaves or the starting of dieback for the season.

Summer Dormancy

These need a shady and airy place to sleep through their dormancy. Many of them start root growth in late summer, so having them in their pots from late summer onwards is beneficial. I keep these potted while dormant, unless there is a problem to attend to. I use a bit of polycarbonate roofing material (twin wall) attached to my fence with hinges (so they are light and easy to lift). The shelves are set up under these. Watch for rodents (rats and squirrels in my area) and figure out how to handle them if they appear to be problems.

I hope this helps you grow these little wonders on your own! Enjoy!

Kukumakranka - the wonderful edible fruits of Gethyllis bulbs

Kukumakranka - except the "K" letters represent clicks in the seemingly extinct Southern African language of the Koina people - besides being a name I cannot reliably accurately pronounce, names a group of bulbs, or rather their fruits. In botanical latin, the species below is Gethyllis verticillata.

 

My son describes the taste of this, the very first fresh fruit of this group I've managed to grow in California thus: "watery and tart, with a fruity fragrance". The fragrance of the fruit is intense and pleasant. To my spouse it is like "fruit cocktail in sweet syrup but with a slightly perfume-y strong strawberry component added to the flavor". 

 

The fruit has about the texture of a very ripe strawberry, with a lot of seeds that are soft and easily chewed - and which taste like the rest of the fruit.

A note about plant names - the useful part of the plant seems to most often be named first, then the rest of the plant gets that name applied, often with a nod to it denoting the rest of the plant rather than just the interesting bit. Examples are "Apple" and "Apple Tree", or "Walnut" and "Walnut Tree".

In rare cases, the plant has more than one amazing or useful bit - for example, the Oak Tree bears Acorns, not "oak tree nuts". In Hawaiian, the 'Ohia tree has the Lehua flowers.

In the case of Kukumakranka, the fruit is the bearer of the name, with the name of the plant or the bulb from which it arises seemingly lost.

These bulbs are from Winter rainfall/Summer dry deserts of South Africa, Botswana, and Namibia (with the exception of two species from the Summer rainfall areas of the Nama Karoo).

There are about 32 described species of Gethyllis. While many of them are rare, mostly due to being quite localized and/or habitat conversion, many remain abundant enough for the fruits to be made into brandy and show up in local markets when in season.

The flowering is day length triggered - flowers appear about one week after the longest day of the year. As these bulbs live in the ground, they must have some sort of clever strategy to keep aware of day length changes. (See light pipe leaves). The flowers push right out of the bare ground without any leaves. In fact, when in flower, only the flower is above ground. When in fruit, only the fruit is above ground, and when in leaf, only the leaves are above ground. At no point in the growth cycle do I get two of these at the same time!

  This is Gethyllis villosa, named for its hairy leaves.

 

A Tale of Two Soils

Meet Lupinus microcarpus variety densiflorus! This California native is part of a species group that can be found all the way from Canada to Argentina. Even better, it is easy and fast to grow, since in the wild it is an annual - a plant that must grow from seed to flower and to mature seeds again in a season or two, and which dies and exists only as seeds in the ground for part of the year.

This year I thought I would help them grow even faster by planting them in a vegetable garden type of potting soil. That produced unexpected and bad results - growing them in a mineral poor, low nitrogen, fast draining soil make awesome plants, while growing them in rich garden soil results in simply not growing them. Why?

This is a tale of the right soil, the wrong soil, and how to tell which is which for a given plant.

We grow a lot of desert and California native plants. A lot of these are specialists in odd, highly inorganic soils, such as serpentine soils. Lupinus microcarpus var. densiflorus is not terribly fussy about soils, being found all the way from Canada to Argentina. What it demands is a well aerated soil.

Below are some of our seedlings in two very different soils. The square pot at the top shows a healthy seedling. The yellowing seedlings in the lower trough are not at all happy. These are growing side-by-side. Why the droopy yellow leaves on the lower plants?

The poor health of the lower plants is a direct result of the soil. It is a commercial potting soil (for containers). Tomatoes grow well in it, as do our parsley, nasturtiums, peppers, and beans. This species does not.

The sickly plants have brown roots. Healthy roots are almost always, at least when small, white. This is true for this annual Lupine - when we unpotted the plant shown above to examine it's roots, here is what we found:

This is the species planted in our "desert bulb mix", which is 3 parts Pearlite, 1 part silver 80 grit blasting sand, and 3 parts rehydrated coir (like peat moss, but sustainable)(parts are measured by volume here). Water drains quickly through it, there are low levels of nutrients, and it is very difficult to turn it sour or make it go anaerobic. Notice the long, white roots visible at the bottom center. These pots are 3" square and 7" deep for scale. This is a textbook healthy and happy young plant.

When we unpotted the others in the trough, we found completely different roots.

These roots are shorter and very brown. They are fighting for their life. Notice how dark the soil is and how it sticks to the starter pot. Compare the texture of this soil with the soil above.

This soil is almost pure compost as purchased - we added most of the sand and whatever pearlite it contains. Vegetables grow fantastically well in this stuff, desert plants are not as fond. Key things to notice - there are fewer air spaces, and a lot of fine grained organic material that forms a sticky "mud" for lack of a more concise term.

The effect of the soil on the plant is dramatic. Soils are not a one-size-fits-all affair. Watch the plant - we have read to some of our plants from various garden books, and it appears many plants are illiterate. They will, however, communicate clearly when they are happy and when they are not. Listen to the plant, take guidance from a book, but if the plant and book differ, then listen to the plant!

These are some photos of the species in the wild this year in California. Notice that this is a sandy soil, yet one that has a very low organic material content and a coarse, aerated structure.

Building Seed Cleaning Machines - Seed Differential Sedimentation

Ever have a fistful of seeds and chaff and sticks from some random wild species and all you want is just the clean seeds?

Sound familiar?

Then you need a Seed Cleaning Machine! Problem is, most of the ones you can buy were designed for specific crops, such as "grains" or corn or such. If you do get lucky and find a highly adjustable type suitable for wild seeds, they are likely the sort where there is a big tube and a screen, and in the process of cleaning the seeds you blow chaff all over the general area - and you still cannot separate seeds from heavier debris.


After building seed cleaning machines based on winnowing or fanning machine designs for the past several decades, I decided we could do better.

Here was my list of objectives:

• Separate seeds from everything else
• No adjustments needed
• Kid friendly
• Easy to build
• Captures all the chaff without making a mess!
• Insensitive to batch size

How to accomplish this list? Applied Physics! The path a feather takes on a windy day and the path of a stone are very different. Let's make use of that observation and build a machine.

In the chart above, the three forces on the seed are drawn. They do not balance, so the seed accelerates along a path. For simplicity, here are the terms in the equations above - two equations are aerodynamic drag, and one is acceleration due to gravity:

• Fg is the force the seed experiences due to gravity
• Fa is the force the seed experiences due to the horizontal flowing air
• Fz is the force the seed experiences due to falling through the air
• A is the cross-sectional area of the seed, in square meters
• Cd is the coefficient of drag, generally 0.4 to 2.0, lower numbers are for smooth shapes, higher numbers are for angular or rough shapes
• Vz is the speed of the seed falling through air, in meters per second
• Vx is the difference between the horizontal airflow speed and the horizontal speed of the seed
• p is the density of air, generally around 1.2kg per cubic meter at sea level
• m is the mass of the seed, in kilograms (a small number!)
• g is the acceleration due to gravity at planet surface, about 9.8 meters per second squared

Putting the equations above into a spreadsheet and running small time steps (0.02 second) for a 1mm x 2mm seed weighing 40mg each and for air flowing from the right at 1.0 meters per second creates this path for the falling seed:

Heavier seeds fall more vertically, while lighter seeds of the same size will fall at an even shallower angle than shown.

This is all theoretical. What happens in real life?

This is a batch of seeds for Fritillaria agrestis, a wonderful plant that has become moderately rare since it liked to grow in places that are now largely farms or cities in the Central Valley, among other locations. The heavy seeds are covering a small range of bins on the right, while chaff and unfilled seed coats (bad seeds) are spread out on the left. I would call this a good separation.

This is a batch of an onion-like plant named Dichelostemma capitatum, once again with a good separation quality. The input is vertically above the rightmost cup in each case.

The machine we built to do this is basically two slabs of Foam Core Board, separated by a 2cm wide gap. A computer fan is connected to a tetrahedral duct on the right side to provide a smooth sheet of flowing air to the airgap between the slabs, and the seeds are added via a funnel on the upper right.

We are using the linear power supply from my oldest surviving seed cleaner on the right edge of the photo (likely topic of a later post) to control the speed of the fan, with the collector cups separated by short vertical popsicle sticks in the base of the unit. Under the device the collecting cups sit, with a fresh tray of them shown in the lower left. The structure on the left will have to be part of another post, as it feeds into our Vortex Chaff Collector.

It took an hour or two to get all this together once we thought out the design. We are making more and better variants, since this is a lot of fun - hot glue guns, cutting, soldering - all stuff that gradeschool kids can help with.

Happy Seed Cleaning!