Phenology – What happens when

Flowering Purple (or Red) Dead Nettle, with honeybee.Credit Kathryn Simmons
Flowering Purple (or Red) Dead Nettle, with honeybee.
Credit Kathryn Simmons

For ten years I have been keeping phenology records, as a guide to when to plant certain crops, and as a way of tracking how fast the season is progressing.

Phenology involves tracking when certain wild and cultivated flowers bloom, seedlings emerge, or various insects are first seen. These natural events can substitute for Growing Degree Day calculations. Certain natural phenomena are related to the accumulated warmth of the season (rather than, say, the day-length), and by paying attention to nature’s calendar you will be in sync with actual conditions, which can vary from year to year, and are changing over a longer time-scale..

Many people know to sow sweet corn when oak leaves are the size of a squirrel’s ear. By this point, regardless of date, the season has warmed enough to get oak leaves to that size, which happens to be warm enough for sweet corn seed to germinate and grow well. Some people transplant eggplant, melons and peppers when irises bloom; sow fall brassicas when catalpas and mockoranges bloom; and know to look for squash vine borers laying eggs for the two weeks after chicory flowers. Some transplant tomatoes when the lily of the valley is in full bloom, or the daylilies start to bloom.

Lilac is often used to indicate when conditions are suitable for various plantings:

  •   When lilac leaves first form, plant potatoes
  •  When lilac is in first leaf (expanded), plant carrots, beets, brassicas, spinach, lettuce
  • When lilac is in early bloom, watch out for crabgrass germinating
  • When lilac is in full bloom, plant beans, squash, corn. Grasshopper eggs hatch.
  • When lilac flowers fade, plant cucumbers.

Also, recording the dates of the same biological events each year can show longer term climate changes. In Europe, 500 years of recorded dates of grape harvests provide information about summer temperatures during that time. Project Budburst is a citizen science field campaign to log leafing and flowering of native species of trees and flowers across the US each year. Each participant observes one or more species of plant for the whole season.

 Here’s our Twin Oaks Phenology Record so far:

(c) Pam Dawling, 2013

Event 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 Notes
Crocus blooming 26-Jan 25-Jan 6-Feb 10-Feb 28-Feb 17-Feb 30-Jan
Chickweed blooming 8-Feb 1-Jan 5-Mar 10-Feb 13-Mar 19-Feb 13-Feb 15-Feb
Robins arrive 27-Feb 31-Jan 20-Jan 26-Feb 2-Mar 14-Feb
Henbit blooming 14-Mar 7-Mar 12-Jan 6-Jan 7-Feb 20-Feb 22-Mar 2-Mar 15-Feb 15-Feb
Daffodils blooming 17-Mar 9-Mar 7-Mar 1-Mar 22-Feb 3-Mar 5-Mar 15-Mar 3-Mar 17-Feb Plant potatoes
Dead-nettle blooming 18-Mar 6-Mar 7-Mar 8-Mar 14-Mar 9-Feb 24-Feb 13-Mar 21-Jan 22-Feb 10-Feb
Spring Peepers first heard 4-Mar 11-Mar 10-Mar 3-Mar 3-Mar 6-Mar 11-Mar 28-Feb 23-Feb 5-Mar Plant peas
Overwinter Grasshoppers seen 26-Feb 4-Apr 25-Feb
Maples Blooming 10-Mar 6-Mar 15-Mar 12-Mar 28-Feb
Dandelion blooming 16-Mar 16-Mar 24-Jan 1-Jan 3-Mar 17-Mar 9-Mar 8-Mar 19-Mar Sow beets, carrots
Forsythia blooming 13-Mar 12-Mar 28-Mar 10-Mar 23-Mar 13-Mar 17-Mar 21-Mar 15-Mar 12-Mar 15-Mar Plant peas. Crabgrass germinates.
Peach blooming 15-Mar 25-Mar 26-Mar 25-Mar 13-Mar
Cabbage White Butterfly 25-Mar 20-Mar 7-Mar 8-Mar 11-Mar 6-Apr 24-Mar 12-Mar 14-Mar Dutch white clover blooms
Harlequin bugs 10-Apr 13-Mar 26-Mar 12-May 16-Apr 29-Apr 14-Mar
Johnny Jump-up blooming 16-Mar 30-Mar 14-Mar 20-Mar 3-Apr 17-Mar
Flowering Cherry blooming 27-Mar 4-Apr 3-Apr 1-Apr 6-Apr 25-Mar 17-Mar 18-Mar 20-Mar
Asparagus spears 6-Apr 4-Apr 4-Apr 5-Apr 6-Apr 6-Apr 21-Mar 19-Mar
Redbud blooming 5-Apr 13-Apr 9-Apr 3-Apr 2-Apr 7-Apr 9-Apr 7-Apr 4-Apr 19-Mar Expect flea beetles
Smartweed germinating 15-Apr 10-Apr 15-Apr 6-Apr 11-Apr 1-Apr 23-Mar 20-Mar <149 GDD base 48F
Lambsquarters germinating 20-Mar 20-Mar <150 GDD base 48F
Violets blooming 29-Mar 26-Mar 28-Mar 6-Apr 22-Mar 20-Mar
Morning Glory germinating 27-Apr 10-Apr 3-Apr 26-Apr 24-Apr 25-Apr 22-Mar >349 GDD base 48F
Tiger Swallowtail 19-Apr 29-Mar 15-Apr 16-Apr 18-Apr 10-Apr 28-Mar
Apples blooming 18-Apr 20-Apr 14-Apr 7-Apr 12-Apr 28-Mar
Dogwood (Amer.) full bloom 5-Apr 21-Apr 13-Apr 28-Mar Plant peppers; soil 65 F
Strawberries bloom 13-Apr 11-Apr 14-Apr 12-Apr 4-Apr 2-Apr 15-Apr 6-Apr 8-Apr 30-Mar
Lilac full bloom 16-Apr 20-Apr 21-Apr 22-Apr 19-Apr 21-Apr 14-Apr 18-Apr 1-Apr Plant beans, squash
Crimson Clover blooming 29-Apr 2-May 16-Apr 22-Apr 23-Apr 27-Apr 18-Apr 25-Apr 4-Apr
Whippoorwill first heard 1-May 22-Apr 15-Apr 24-Apr 17-Apr 25-Apr 8-Apr 14-Apr 5-Apr
Galinsoga germinating 1-May 22-Apr 16-Apr 20-Apr 6-Apr
White Oak “squirrel’s ear” 20-Apr 26-Apr 23-Apr 26-Apr 25-Apr 14-Apr 23-Apr 12-Apr Plant sweet corn
Tulip Poplar blooming 2-May 10-May 3-May 26-Apr 3-May 6-May 26-Apr 28-Apr 17-Apr Plant sw corn 200 GDD base 50F
Ragweed germinating 20-Apr 16-Apr 25-Apr 26-Apr 21-Apr Plant sw corn 200 GDD base 50F
Last Frost 24-Apr 4-May 3-May 1-May 8-May 17-Apr 19-May 10-May 14-Apr 25-Apr Average 4/30 (10 yrs)
Fireflies 7-May 2-May 1-May
Colorado Potato Beetle adult 22-May 3-May 7-May 29-Apr 27-Apr 3-May 25-Apr 2-May
Strawberries ripe 10-May 17-May 12-May 10-May 7-May 15-May 3-May 10-May 7-May
Purslane germinating 26-May 8-May 22-May 5-May 20-May 15-May 8-May
Baby Grasshoppers 12-Jul 30-Jun 26-Jun 17-Jun 16-May
Cicada first heard/seen 14-May 5-Jul 3-Jul 29-Jun 17-May
Hardneck garlic mature 14-Jun 19-Jun 13-Jun 5-Jun 4-Jun 30-May 9-Jun 11-Jun 6-Jun 31-May
Foxgloves bloom 6-Jun 11-Jun 8-Jun Bean beetle eggs hatch
Bean Beetle eggs 4-Jun 16-Jun 10-Jun 6-Jun 20-Jun Hatch when foxgloves bloom
Japanese Beetle first seen 16-Jun 21-Apr 15-Jun 20-Jun 29-Jun 21-Jun 850 GDD (base 50F)
“June” Bugs first seen 5-Jul 11-Jul 2-Jul 12-Aug 10-Jul 30-Jun 29-Jun 30-Jun 23-Jun
Corn Earworm first seen 28-Jul 8-Jul 12-Jul 10-Jul 14-Jul 150-490 (base 54F)
Fall Dead-nettle germinating 1-Sep 20-Aug 30-Aug 20-Aug 16-Aug 20-Aug 15-Aug 29-Aug 18-Aug Plant spinach
Fall Henbit germinating 28-Aug 20-Aug 29-Aug 18-Aug
Fall Chickweed germinating 7-Sep 7-Sep 5-Sep 6-Sep Plant spinach
First Fall Frost 3-Oct 6-Nov 27-Oct 13-Oct 29-Oct 20-Oct 19-Oct 23-Oct 30-Oct 22-Oct Average 10/22 (9 yrs)
Harmonia Ladybugs migrate east 18-Oct 12-Nov 21-Oct 27-Oct
Garlic planted (hardneck) 25-Oct 20-Oct 9-Nov 3-Nov 11-Nov 1-Nov 5-Nov 11-Nov 15-Nov 6-Nov Soil temp 50 F
Event 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 Notes

Home from CFSA, Superstorm Sandy

Beauregard sweet potato
Photo Southern Exposure Seed Exchange

Superstorm Sandy didn’t do us much damage, luckily. It’s been raining for 40 hours, but we’ve only got 2.8 inches so far and it looks like it’s going to clear up later today. Despite my worries about the broken hoophouse windows blowing in and us losing our newly re-plasticked hoophouse, it didn’t happen. We didn’t have any really high winds, and we didn’t even lose power, but of course we did all the prep work.

Georgia Jet
Photo Southern Exposure Seed Exchange

Yesterday we re-stacked our sweet potatoes which had finished curing (the skins don’t rub off any more). We moved them into a wire rodent-proof cage, and close-stacked them, taking away all the sticks that spaced the boxes during curing. I haven’t got numbers for the total yield yet, but it comes to 96 boxes. The Georgia Jet produced 42 boxes and the Beauregard only 32 from the same length row. Our two heirloom varieties produced three boxes each. We don’t expect many of them, but we are keeping the varieties alive, because genetic diversity is important and who knows what secret virtues these varieties have?

We also bravely spent time in the rain, digging drainage ditches to reduce the impact of the hurricane. They seem to have worked quite well. And we draped the soggy rowcovers over the frost tender crops, in anticipation of freezing conditions.

While I was away at the CFSA Conference, the crew harvested the white potatoes. We got a good yield (also no numbers yet), but we got a disappointingly large number of greened potatoes. (Green from being exposed to the light.) I think the reason is that our new experimental tractor-mounted furrow-making disks don’t make furrows as deep as we need. The walk-behind BCS furrower on the rototiller made adequate furrows, but not as good as the old Troybilt furrower. This flags a need to research better gear before March.

I had a great time at the CFSA Conference. I think there were about 700 people there. About 70 came to my workshop Growing Great Garlic, on Saturday afternoon. They were very appreciative, and I managed OK without my notes! It’s not as bad as it sounds – I had a slideshow and had practiced quite a few times, and knew it better than I would have guessed. Somehow I couldn’t get my notes on the laptop screen without them also appearing on the big screen along with lots of clutter. This flags a need to find out before my three workshops at the Southern Sustainable Agriculture Working Group conference in Little Rock, Arkansas, January 23-26. Busy, busy.

The conference was very well organized and the food was spectacular – mostly local and sustainably grown. I had the chance to attend several workshops by other people. Tony Keinath, the vegetable pathologist at Clemson University, talked on Sustainable and Organic Approaches to Managing Cucurbit and Tomato Diseases – a very well-prepared and information-packed session. I feel in a better place to tackle next year’s plagues now. I was struck by the fact that he had seen NO benefits of using Oxidate, the hydrogen peroxide disease control product.

A workshop I found particularly valuable was Laura Lengnick‘s presentation “Is Your Farm Climate Ready?”  She is doing valuable work to help farmers get ready for climate variability. She is one of the main authors of a USDA ARS report Climate Change and Agriculture: Effect and Adaptation. Its publication date is November 14 2012. She also spoke at the August 2012 symposium of the Ecological Society of America, Climate change impacts on agricultural systems:

She suggests viewing climate change as yet another production risk to assess and prepare for. The vulnerability of your farm has two components: exposure and adaptive capacity. As far as vulnerability, the most immediate key exposure is water issues (too much and too little). Rising air temperatures, including night temperatures, more extreme temperatures provide threats and some opportunities. Increasing CO2 levels will provide some positive effects such as faster crop growth. As far as adaptive capacity, the main feature of that aspect is our personal capacity to respond and plan. Laura Lengnick says “Greater attention to climate as critical for decision-making is expected by future generations of producers.” We need to start with ourselves.

Baby ginger, ready to be eaten, pickled, candied, frozen.
Photo East Branch Ginger

Next I attended a workshop by Susan Anderson of East Branch Ginger, and learned so much about how to do the best by this crop, that I am looking forward to an even bigger harvest next year. This year we harvested 165 pounds, and saved 65 pounds as seed stock, so we can plant a bigger patch in next year’s hoophouse.

Harvested baby ginger, about 6 months old
Photo East Branch Ginger

Meanwhile I’ve finished my next article for Growing for Market. My working title is Knowing When to Take Action. It’s the third part of my series on being a resilient farmer. This article includes scouting and monitoring for pests and diseases; using pest and disease forecast services; and being prepared for the effects of extreme high and low temperatures. When is it time to cut your losses? A big part of the article is a table of soil temperatures to help when deciding planting and harvesting dates.