Newsletter Cochise County Master Gardener High on the Desert Vol. 26, No. 12 December 2015 The University of Arizona and U.S. Department of Agriculture Cooperating The Virtual Gardener—The Science of Seeds ‘Tis the Season—time for long winter document is Seed Germination Theory naps and visions of next year’s garden to and Practice, Second Edition which be dancing in your head. It’s also a time comes with a First and a Second for perusing seed catalogs and beginning supplement. to think about starting seeds indoors to Dr. Deno regarded seed germination as get an early start outdoors next spring. a chemical process initiated by reactions This month I want to talk about a controlled by environmental factors. The fantastic resource for seed starters processes vary by species and are developed by a scientist most gardeners designed to promote the survival of a have never heard of, Dr. Norman Deno. species in its native environment by Inside this issue: Dr. Deno was a delaying germina- professor emeritus “I highly recommend Dr. Deno’s tion until environ- Let’s Plant Roses 2 of chemistry at book and the supplements.” mental conditions Ready, Set . Grow! 3 Pennsylvania State are just right for the Cuttings “N’ Clippings 4 University who late in his career turned survival of the seedlings. For example, Become a Master Gardener 4 his attention to horticulture. He was one the seeds of plants native to cold Gratitude Revealed 4 of the first researchers to apply the climates should not germinate immedi- At a Glance Box 5 methodology of chemistry to the study ately in the fall but wait until the Palmleaf thoroughwort 5 of seed germination. He experimented weather warms up in the spring. Similar- with thousands of different seeds and ly plants native to regions with wet and along the way not only illuminated the dry seasons delay germination to periods processes of germination, but also when moisture is available. Different developed practical techniques for plants—sometimes even closely related gardeners to use in starting their own species—may employ different mecha- seeds. His work is documented in three nisms to achieve the same delay in publications that are available free for germination. According to Deno, about download in pdf format from the U.S. (Continued on Page 2) Department of Agriculture. The basic Cochise County Cooperative Extension www.ag.arizona.edu/cochise/mg/ 1140 N. Colombo, Sierra Vista, AZ 85635 450 S. Haskell, Willcox, AZ 85643 (520) 458-8278, Ext. 2141 (520) 384-3594 P AGE 2 (Continued from page 1) Let's Plant Roses! 95 percent of the species he with multistep and extended studied used chemical methods to germinations, and he often (Editor’s Note: This article written by delay germination and only 5 achieved germination rates above Bill Schulze was adapted from a De- percent used physical methods. 90 percent using it. To use this cember 2012 article published in the Sierra Vista Herald.) Chemical methods operate by method, the seeds are placed on a controlling the initiation of moistened paper towel enclosed in Toward the end of this month and complex chemical reactions a polyethylene sandwich bag. The into the first months of the new year, within the seed and the rates at bags are kept in heated or cooled bare-root roses and bare-root fruit which those reactions proceed. environments according to the trees will be widely available in Temperature, moisture, light, and needs of the seeds being germinat- nurseries. So if roses or fruit trees the external presence of certain ed. Deno used only two tempera- are something you’ve got a hanker- plant hormones called gibberel- tures for his experiments—40˚F ing for, keep your eyes open and lins, especially Gibberellic Acid- for chilling and 70˚F for warming. your shovel handy. When planting 3 (GA-3), produced by microor- Some seeds germinate at only one bare-root plants, soak the roots of ganisms in the soil are the factors temperature and others require the plant in water for a few hours (no most frequently used. Sometimes both chilling and warming. His longer than a day or two) prior to a single factor controls germina- germination reference lists in- planting. Dig a hole two or three tion but more frequently a dicate the requirements for times larger than the root ball, but no number of different factors hundreds of different species. deeper. Cut off damaged roots and operate in combination to pro- Once the seeds have sprouted in gingerly untangle and spread out the duce the desired effects. the paper towels, they are trans- remaining roots. Place the plant in The most common physical ferred to pots to grow into the hole and refill with the native method is usually called seedlings. soil you just removed. Water well to “scarification,” although the In addition to heat and moisture, eliminate air pockets and do not method has nothing to do with Deno found that treatment of compact the soil by tamping with creating a scar. Dr. Deno ab- seeds with GA-3 significantly your feet. Don’t amend the soil or horred the use of that term and improved his germination rates. add fertilizer for the first year, alt- preferred the term “puncturing.” Gibberellic acid is a naturally hough it is a good idea to remove Whichever term is used, the occurring, growth-promoting hor- stones and rocks. Do not plant a tree purpose of the technique is to mone that is produced by plants or shrub deeper than it’s roots re- breach the impervious coating of and microorganisms. A search of quire. Planting too deeply exposes some seeds to allow water and/or the web will locate a number of the bark of the trunk to rotting. If the oxygen to reach the embryo and sources where this product can be plant is grafted, as most roses and initiate the sprouting reactions. purchased. fruit trees are, plant so that the bud The technical details of how Growing plants from seed is a graft union is two or three inches seeds germinate is fascinating and very cost-effective way of above the soil line. Keep the soil well worth reading, but the populating your garden, especially moist but don’t overwater as water practical methods Deno used to with landscape plants that are needs are slight while the plant is sprout seeds along with his expensive to buy in the nursery. dormant. extensive lists of the best condi- Many landscape plants have As the holiday season nears, living tioning and germination tech- produced seeds over the summer Christmas trees will be for sale in niques to use for different plants that can be harvested now and nurseries. If you buy one and want to will probably be of more interest started over the winter for plant it, look for a tree that is to many gardeners. planting next spring. If you are adapted to our climate. Pine trees Deno used several methods for interested in seed-starting, I that will do well here include the germinating seeds, but one of the highly recommend Dr. Deno’s Aleppo Pine (Pinus halepensis), the germination techniques he book and the supplements. Afghan Pine (Pinus elderica), and pioneered was the “baggie and the Italian Stone Pine (Pinus pinea). Gary Gruenhagen, Master Gardener paper towel” method. This was [email protected] Both the Aleppo and Afghan pine his method of choice for species are fast growing. The slower grow- (Continued on page 4) P AGE 3 Ready, Set . Grow! During my undergraduate “The seeds just won’t germinate.” If you would like more information and graduate studies at New Mex- Often times they were just watering on propagating and care of Penste- ico State University I belonged to and giving it too much TLC. mon there is an American Penste- a student organization known as There are more than 250 Pen- mon Society website with lots of the NMSU Hort Forum. One year, stemon species and they are quite information. Check it out here: we collaboratively worked on a diverse in their selection of where to http://apsdev.org/. club T-shirt and decided it would grow. More than twenty cultivars Since the majority of Penste- be fun to not just display our stu- have been given the Award of Gar- mon flowers are in the reds, pinks, dent club logo on the front, but den Merit by the Royal Horticultural and blues it can be really striking to also include funny or clever Society and here is a link to their interplant with yellow and white quotes that finished the line “You website if you are looking for vi- colors and textures. I would suggest might be a horticulturist if brant colors, https:// checking the bloom time (some can ____________.” All of us stu- www.rhs.org.uk, just search for be early versus late) for the particu- dents in the club had the assign- Penstemon. From low deserts to lar Penstemon cultivar you are in- ment to work on our own list of high in the mountains, flat plains, terested in and choosing a similar finished statements and we would and in the forests, Penstemon can be bloom time with the other wild- bring them back to a meeting and an outstanding addition as one of flowers. It can make quite an im- vote on the top ten to include on your selections for wildflower to pact! Some popular companion the back of our shirts. brighten up un-used or neglected plants would be Coreopsis species One of the quotes that made it properties.