Love Is In The Air

Daffodils

One of my favorite classes when I attended Cal Poly San Luis Obispo was Plant Taxonomy. On the surface the subject sounds a little dry but the professor was all about plant reproduction which is quite exciting and more varied than you think. So with Valentine’s Day upon us here are some interesting facts about how plants get together and how you can help.

Red flowering quince

If you’re like me you’ve caught a case of pre-spring fever. How can we help it when the flowering plums are covered with hundreds of blossoms, the saucer magnolia flowers are already open, the flowering quince are in full bloom and every acacia in the county is blooming. It’s fascinating to mark time with events in the botanic world. There’s even a word for it- Phenology. Websites like USA National Phenology Network at http://www.usanpn.org/ offer lots of information on the subject.

Phenology is the study of plant and animal life cycle events and how these are influenced by seasonal variations in climate. When do they occur each year? Phenology is a real science that has many applications. In farming and gardening, phenology is used chiefly for planting times and pest control. Certain plants give a cue, by blooming or leafing out, that it’s time for certain activities, such as sowing particular crops or insect emergence and pest control. Often the common denominator is the temperature.

Indicator plants are often used to look for a particular pest and manage it in its most vulnerable stages. They can also be used to time the planting of vegetables, apply fertilizer, prune and so on.

Here are some common garden plants and what they indicate:

When daffodils begin to bloom, sow peas.
When dandelions bloom, plant spinach, beets and carrots.
When lilac leaves are the size of a mouse’s ear, sow peas, lettuce and other cool-weather crops.
When lilacs are in full bloom, plant beans.
Once lilacs have faded, plants squash and cucumbers.
When apple trees shed their petals, sow corn.
When dogwoods are in full bloom, plant tomatoes, peppers and early corn.
When bearded iris are in bloom, plant peppers and eggplants.
When locust and spirea bloom, plant zinnia and marigolds.
When forsythia and crocus bloom, crabgrass is germinating. When this happens the soil temperature at a depth of 4″ is 55 degrees. Treat with an organic pre-emergent.
When crocus bloom, prune roses and feed your lawn.
Mexican bean beetle larvae appear when foxglove flowers open.

Magnolia soulangeana blooming at Filoli Garden

Record your own observations at https://budburst.org/ to start a data base for our area. Another great site is National Sustainable Agriculture Information Service at https://attra/ncat.org/ Sites like these can also help you design orchards for pollination and ripening sequence, design for bee forage plantings, design perennial flower beds and wildflower plantings as well as plantings to attract beneficial insects and enhance natural biological control. How cool is that?

But back to plant reproduction. Mosses reproduce from male and female mosses which produce spores. Conifers produce two type of cones on the same tree. Wind blows the pollen to another cone which combine to make a baby conifer which lives in a seed inside the cone.

Blireiana flowering plum

Then there are the most advanced plants – the flowering plants. Some flowering plants have both male and female flowers. They are monoecious meaning “single house”. Dioecious plants have male flowers on one plant and female flowers on another. Plants that rely on flowers for reproduction are very dependent on outside help such as insects and animals which is where we come in. Be a citizen scientist in your own backyard.