Seed Packet Info

I was wondering if any of you are keeping a garden diary. If so how did your planting results corresponded with the seed packet info on sprouting and harvesting dates? It has been my experience it takes longer to harvest than they say. I know there are variables, but I am interested to hear what is happening in your gardens.

I'm a journal-keeping gardener and I list possible harvest dates and I have to tell you that its always later than I expected from the packet info.
There are so many variables.....sunshine, cool weather, heat.....that the packet info must be based on perfect conditions.
I always add a week or two to the expected dates these days.
I guess Mother Nature hasn't read the seed packets.

FYI, everything takes longer than the packets for me. Carrots are notoriously late. My radishes run about 2 weeks behind the "22 days." And, my lettuces and spinaches would be off if I wasn't such an "early cutter." I like the baby leaves, personally.

I tend to look at those dates and mark them on the calendar with an ABC scenario. ABC being "absolute best case." Then, I don't get too disappointed as that day invariably comes and goes. It really only serves as a "start checking by" date.

Phenologists can tell you within a day or two when a plant will be ready to harvest if it is grown in a greenhouse at a steady known temperature. They know that each type of plant requires X amount of accumulated heat to reach maturation. The units of heat they use are called Growing Degree Days (GDD).

Output from uspest.org/wea crop degree-day/phenology model program:

Model species/general links: sweet corn [Jubilee];

Lower threshold: 50 degrees Fahrenheit
Upper threshold: 86 degrees Fahrenheit

Region of known use: Pacific Northwest

================EVENTS TABLE================
1. 104 DDs after planting: First emergence from soil
2. 308 DDs after planting: 5 leaf stage
3. 445 DDs after planting: 7 leaf stage
4. 883 DDs after planting: 5 inch tassels
5. 960 DDs after planting: 10 inch tassels
6. 1005 DDs after planting: 5% silk emergence
7. 1062 DDs after planting: 50% silk emergence
8. 1145 DDs after planting: 95% silk emergence
9. 1288 DDs after planting: 50% brown silks develop
10. 1412 DDs after planting: 95% brown silks develop
11. 1539 DDs after planting: Fresh market harvest
12. 1597 DDs after planting: Processing market harvest

There are automated weather stations that provide daily accumulated updates for commercial farmers. If the farmer knows that the corn weevil becomes a problem at 1200 GDDs, then he knows when he'll have to take preventative measures. He'll also know weeks ahead of time when to schedule extra manpower for harvest, make transportation arrangements, etc.

You can find out the GDDs in your area by going to
http://www.weather.com/outdoors/agriculture/forecast/
and clicking on the "Growing Degree Days Calculator" link on the left.

I knew I was having a cool spring. Precisely, I'm 26% cooler than average to date.

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Long story short: 'Days to harvest' printed on a seed package are a SWAG. If I plant corn seeds near cool Seattle, and Chopper plants the same seeds at the same time near hot San Diego, she's going to be eating her corn a lot sooner than me. What would be the right number to put on the package?

Growing degree days still makes my brain feel like this: .

I still have to spend a lot of time like this: . Yeah, right, who am I kidding? More like this:

But I love having found out about them, and they really do explain everything, even if I don't yet understand them.

I was just wondering if anyone ever had a harvest on or earlier than the seed packet said as I thought they were an adverage. Thanks Boffer that taught me alot. I will just go back to just harvesting when things are ripe and not worrying about dates. LOL