Learn about your climate <\/strong><\/p>\n\n\n\n It is helpful to learn about\nthe climate in your neighborhood, as it will help you in planning the garden.\nYou can often get useful information about your weather history from local\nweather websites (there is probably some weather buff living close to you who\nposts their own weather data online). You might also contact your local fire\nstation, airport, newspaper, TV station or cooperative extension service\noffice. Surprisingly few weather stations give much useful information that is\nrelevant to gardeners, which is surprising as there are a lot of gardeners out\nthere and the weather affects gardening more than it does most activities. On a\nwider scale I found the Western Regional Climate Center website to be helpful\nsource of information (there is also an eastern one). <\/p>\n\n\n\n Generally the more local the\ndata, the better, as weather can differ considerably in a few miles. I live only\nabout 10 miles away from Santa Cruz, but I\u2019m 2300 ft higher up and a whole zone\ncolder in climate. A rain gauge and maximum\/minimum thermometer will allow you\nto keep your own records. <\/p>\n\n\n\n Latitude <\/strong><\/p>\n\n\n\n Latitude is your distance\nfrom the equator and has a major impact on your garden because it determines\nday length. The further north you go, the longer the days in summer and the\nshorter the days in winter. Long days mean more sunlight and more growth and in the far north the very\nlong days of summer can produce extraordinarily large vegetables. Conversely\nwhen the day length drops below 10 hours in winter there tends to be little\nappreciable plant growth. <\/p>\n\n\n\n Day length<\/strong><\/p>\n\n\n\n In winter your gardening is\nmore limited by day length than it is by temperature (you can raise the\ntemperature fairly easily with cloches). The combination of shorter days and\nweaker sun, means there may be only an eighth as much solar energy around as in\nsummer. <\/p>\n\n\n\n A common rule of thumb is\nthat plants need a minimum of 10 hours of daylight per day to make significant\ngrowth. If they get less than this they grow very slowly, especially when\ncombined with low temperatures. Bigger plants will often keep growing (rather\nslowly) at this time, but smaller ones will essentially come to a standstill.\nThis is because growth is relative to size and a seedling has so little leaf\narea it just can\u2019t produce very much food in the short time it has each day. A\nlarger plant has a greater photosynthetic area and so may still produce a\nsignificant amount of new growth (enough to replace the leaves you remove in\nharvesting).<\/p>\n\n\n\n The dates when the day\nlength drops below 10 hours in fall and when it goes above 10 hours in spring are\nimportant milestones in the garden year. Where I live there are about 4 weeks\non either side of the winter solstice when we don\u2019t get a lot of plant growth.\nGrowth picks up noticeably as soon as we get above the magical 10 hours, and\nmany hardy over-wintering plants start to bolt.<\/p>\n\n\n\n Day length also has another\nsignificant effect in the garden. Plants use the length of the period of\ndarkness to determine when to produce flowers or when to start expanding their\nbulbs.<\/p>\n\n\n\n Altitude<\/strong><\/p>\n\n\n\n For\nevery 1000 feet of elevation gain, the temperature drops by roughly 4\u00b0F (this\nmay be offset by other factors however). This is the main reason why my garden\nis several weeks behinds gardens in Santa Cruz which is only 10 miles away.<\/p>\n\n\n\n Temperature<\/strong><\/p>\n\n\n\n You are no doubt already\naware of the effects of temperature: most plants grow faster in warmer\nconditions, slow down as it gets cooler and stop growing altogether when it\ngets cold (below 45\u00b0F). This happens because the speed of a chemical reaction\nincreases with temperature, so growth is more efficient in warmer weather. Of\ncourse it isn\u2019t quite that simple, because each crop evolved to grow in a\nspecific temperature range. A watermelon requires a lot higher temperature than\nspinach, which actually grows better at lower temperatures.<\/p>\n\n\n\n Precipitation<\/strong><\/p>\n\n\n\n Human beings are creatures\nof the sun and rain is something most people don\u2019t give a second thought to,\nexcept as an inconvenience. Until you have nursed plants though an extended\ndrought, it\u2019s hard to appreciate the near-miracle of water falling from the sky\nand landing right on your garden beds. The fact that much of it then sits in\nthe soil until needed by the plants is another amazing thing. Yet another\nmiracle is that when it falls as snow in the mountains it sits there for months\nbefore melting in summer and gradually running down to us.<\/p>\n\n\n\n As gardeners we should be\nmore appreciative of rain, because it isw mor 3eimportant for good garden\ngrowth than almost anything else. In particular we should think about the\nrainwater that falls on our property and where it goes. We should try and\nensure that any rainfall that lands on our garden has a chance to soak into the\nsoil, rather than running away down storm drains. An inch of rain adds up to\naround 27000 gallons per acre, which at 1.5 cents per gallon adds up to around\n$400. I hesitate to quantify and put a price on nature, but I mention this to\nshow how much she gives that we take for granted. <\/p>\n\n\n\n Rainfall can vary enormously\nfrom year to year, even in temperate climates. One year may endless rain and\nwaterlogged soil, while another may bring endless sunny skies and parched soil.\n<\/p>\n\n\n\n An over-abundance of rain\ncan be a mixed blessing in the vegetable garden. It is vital for plant growth\nof course and without it we can\u2019t grow anything, but too much water becomes a\nproblem. It can saturate the soil and drive out all of the air, cause erosion\nand leach out nutrients. If plant leaves stay wet for too long it can\ncontribute to a variety of plant diseases and pests. Persistent heavy cloud\ncover also reduces the amount of sunlight reaching the plants.<\/p>\n\n\n\n Frost<\/strong><\/p>\n\n\n\n Frost is something all\ngardeners outside of the tropics have to learn how to deal with. It occurs when\nthe temperature drops below freezing point, causing any liquid water in the air\nto turn into ice. When this occurs tender plants will be badly damaged, or\nkilled, as the water in their cells freezes. Hardy plants contain their own\nanti-freeze and will be undamaged by the same temperature. <\/p>\n\n\n\n In temperate climates frosts\noccur at both ends of the growing season, though exactly when they occur can\nvary by many weeks from year to year. The growing season is defined as the\nfrost free period between the last killing frost of spring and the first\nkilling frost of autumn. In areas with very short growing seasons frost can be\nan almost constant threat. <\/p>\n\n\n\n Frost occurs in two distinct\nforms, radiation frost and advective frost. Radiation frost occurs when the\nground gradually radiates heat through the night until it drops to freezing\npoint. This effect occurs over a wide area, but is most severe in places that\nare wide open to the sky. Advective frost is more localized and occurs when\nsinking cold air accumulates in low-lying valleys and hollows. These are known\nas frost pockets and you may see them white with frost, even though areas\nnearby are untouched. Wooded areas are less affected by frost because the trees\nslow down cold air movement, and limit heat loss through radiation. <\/p>\n\n\n\n The effects of frost are\nrarely uniform and they can assist you in locating the warmest and coldest\nareas of the garden. The areas where frost is thickest are the coldest, while\nareas with the lightest frost (or none at all) are the warmest. To find out if\na low spot is a frost pocket just go outside after a very mild frost. The areas\nwith frost on them will be the frost pockets. <\/p>\n\n\n\n Frost doesn\u2019t kill plants\nuniformly. A sudden early cold spell in November might kill plants overnight,\nwhereby a colder spell in January (when plants are more hardened) might not\naffect them at all. Wet soil exacerbates freezing by conducting heat more\neffectively. Deep snow acts as insulation and protects plants from severe cold.\nCold air is heavy, so the higher parts of a tree may be unaffected by frost,\neven though lower branches are hard hit.<\/p>\n\n\n\n Frost isn\u2019t always bad, in\nsome situations it may even be beneficial for the gardener. It can kill insect\npests and gives fruit trees their needed chill hours. <\/p>\n\n\n\n The average <\/strong>last spring frost date <\/strong><\/p>\n\n\n\n The last frost of spring is\nan important event in the gardening year, because it marks the start of the\ngrowing season. It is commonly used as a reference point as to when to start\nplanting various crops (4 weeks before the last frost, or 2 weeks after the\nlast frost). <\/p>\n\n\n\n It would take a crystal ball\nto accurately predict when the last spring frost is going to occur in any given\nyear, but we can get a good idea of the probable date by looking at historical\nrecords. If you look at the dates when last frosts have occurred each year over\nan extended period, you can come up with an average date on which it occurs\n(this doesn\u2019t take into account climate change, but it\u2019s the best we can do). <\/p>\n\n\n\n The average date of last\nfrost is just that, an average and 50% of last frosts will occur after this\ndate and 50% will occur before it) The earlier before this date the more likely\nthere will be frost and the further past it the less likely. Because this is\nonly an average, it can sometimes seem rather disconnected from reality. For\nexample my average last frost date is the 23rd<\/sup> March, but I have\nknown the last frost to occur in late February and towards the end of April.\nDespite the ambiguously average nature of the average date, it is useful as a\nbaseline to work from (just don\u2019t be surprised if the last frost occur long\nbefore or after this date). <\/p>\n\n\n\n The variability of the last\nfrost date presents you the gardener with a dilemma, as you know there is a 50%\nchance of a frost after that date. You could be conservative and wait a while\nlonger before planting, to be better assured <\/p>\n\n\n\n of success. However this may\nwaste valuable growing time, which can be important if spring (or the whole\ngrowing season) is short. It sometimes makes sense to plant early and be\nprepared to protect your plants if frost is predicted (or risk the possibility\nof frost damage). <\/p>\n\n\n\n The significance of the last\nfrost date depends upon what crop you are planting. It doesn\u2019t have much\nrelevance for the frost tolerant cool weather crops, such as the Brassicas,\npeas, spinach, lettuce or carrots. They can germinate in cool soil and a little\nfrost won\u2019t harm them at all. Even relatively tender crops like potatoes aren\u2019t\nusually adversely affected (if frost threatens you can easily cover them, as\nthey will be barely out of the ground). It is most important for the warm\nweather crops, such as tomatoes, peppers and beans that don\u2019t grow well in cold\nsoil and can be killed by frost. Once you have planted these crops you need to\nkeep an eye on the weather and if frost is predicted you must protect them with\nstraw mulch, frost blankets or other devices.<\/p>\n\n\n\n First fall frost date<\/strong><\/p>\n\n\n\n The first killing frost in\nfall is also an important event because it will terminate the growth of any\ntender plants that aren\u2019t protected. It marks the end of the \u201cgrowing season\u201d,\nthough of course it doesn\u2019t necessarily mean the end of your vegetable garden.<\/p>\n\n\n\n You can usually extend the\ngrowth of your tender plants at this time of year, by protecting them with\nfrost blankets, mulch or cloches. Doing this can often earn you a few extra\nweeks of growing before cold weather finishes them off. When serious cold\nthreatens your tomatoes and peppers, you should harvest any fruit that is\nnearly mature and ripen it indoors. This is always worthwhile as it can give\nyou another few weeks of fruit.<\/p>\n\n\n\n Finding your first and last frost dates<\/strong><\/p>\n\n\n\n I found the Western Regional\nClimate Center website to be very helpful (there is also an eastern one) for\nfinding these dates. My area is covered\nby the Northern California climate summaries map at http:\/\/www.wrcc.dri.edu\/summary\/climsmnca.html <\/p>\n\n\n\n This map showed my closest\nweather station to be in Ben Lomond, so I clicked on that page. On the left of\nthe page under Temperatures I found Spring \u2018Freeze\u2019 Probabilities. This brings\nup a graph showing the probability of the occurrence of various temperatures\naround freezing. Where the orange (32\u00b0F) line bisects 50% is the average last\nfrost date, which for Ben Lomond I estimated to be about the 23rd of March.<\/p>\n\n\n\n The first fall frost date is\nalso found under Temperatures as Fall \u2018Freeze\u2019 Probabilities, and has a similar\norange (32 degree) line. Where this bisects 50% is the average first fall frost\ndate. For Ben Lomond I estimate this to be about the 12th<\/sup> of\nNovember.<\/p>\n\n\n\n There is also a \u2018Freeze\nFree\u201d Probabilities page, which has a graph showing the length of your frost\nfree season. For Ben Lomond I estimate this to be about 240 days.<\/p>\n\n\n\n Of course these dates are\naverages and so will vary from year to year (some years it will be earlier and\nsome years it will be later). In my case I live about 2000 feet above Ben\nLomond, which would affect my frost date, but Ben Lomond is in a valley where\ncold air collects, so I\u2019m not sure how much (often I drive down into frost in\nthe valley bottom).<\/p>\n\n\n\n The seasons<\/strong><\/p>\n\n\n\n Unless you live in the\ntropics, you have to deal with the seasons, which dictate what you can plant\nand when you should plant it. They are caused by the tilting of the earth,\nwhich makes the days shorter or longer. The earth receives solar heat in the\ndaytime and loses solar heat at night, so the proportion of day and night\ndetermines whether the earth gradually gains heat or loses heat day by day.\nDuring the long days and short nights of summer the land gradually gets warmer.\nIn the winter the long nights and short days cause the land to gradually gets\ncooler. This gradual heat change explains why the warmest days are after the\nsummer solstice and the coldest ones are after the winter solstice. <\/p>\n\n\n\n The tilting of the earth\nalso affects the apparent strength of the sun. In summer the sun is warmer\nbecause it strikes the earth at a more direct angle and so the energy is\nconcentrated on a smaller area. In winter it feels weaker because it strikes\nthe earth at a more oblique angle, so its energy is spread over a larger\narea (and I thought it was because we\nwere further from the sun!) Of course we see this effect every day as the suns\nangle changes in the sky, it is weaker in the morning and evening than it is at\nmidday.<\/p>\n\n\n\n In cold climates the growing\nseason is often rigidly defined, as the ground may be frozen for months and all\nplant growth comes to a halt. In milder climates the differences are much less\nclear cut. My garden gets occasional frosts and snow, but much of the time it\nis so mild that many hardy crops keep on growing quite happily. In such places\nday length gives you a more useful definition of the growing season. <\/p>\n","protected":false},"excerpt":{"rendered":"![\"\"](\"https:\/\/greenmanpublishing.com\/wp-content\/uploads\/2020\/04\/frost-dams.jpg\")
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