Vegetable and Weed Degree-day Models

Croptime introduces degree-day (DD) models for vegetable varieties and weeds. Vegetable models can help schedule planting dates and predict harvest dates. Initial findings indicate that DD models are more accurate than calendar days at predicting harvest. Weed models can predict development of first germinable seed, and help reduce the risk of weed seed rain. To date we have:

  • Four transplanted broccoli models
  • One transplanted and six direct-seeded cucumber models
  • Three models predicting first viable seed set for hairy nightshade, lambsquarter and redroot pigweed

New models will be posted online when available. Sweet pepper and sweet corn models are coming soon. Spinach, carrot, parsnip, lettuce, cauliflower, cabbage, kale, summer squash, snap bean and tomato models will be online by spring 2017.


Croptime Calculator

Quick Guide: Tri-fold brochure with step-by-step guide to using Croptime

Educational Slides: 53 Croptime workshop teaching slides. Request PowerPoint format from Nick Andrews

Croptime Growth Stage Guide: 38-page guide that describes vegetable growth stages and provides instructions and a data sheet for collecting crop development data for new vegetable degree-day models.

Organic Fertilizer and Cover Crop Calculators - link to another Small Farms page


If you have questions or comments or are interested in helping to collect data for new Croptime models, please contact Nick Andrews for more information.

Contact Heidi Noordijk to receive announcements about future Croptime workshops.