CMG GardenNotes #717 Growing Tomatoes

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1 CMG GardenNtes #717 Grwing Tmates Outline: Variety selectin, page 1 Planting, page 2 Planting time, page 2 Selecting the ideal plants, page 3 Space and trellis plants, page 3 Mulching, page 5 Irrigatin, page 5 Fertilizatin, page 5 Pllinatin and summer temperatures, page 6 Garden sanitatin, page 6 Rtatin, page 7 Fall clean-up, page 7 Cmmn disrders, page 7 Ripening fruit at the end f the seasn, page 7 Ripening fruit indrs, page 7 Variety Selectin There are ver 2,000 cultivars f tmates grwn wrldwide. Ask neighbrs, lcal gardeners, and garden center staff abut lcal favrites. Hybrid tmates are ppular in the United States t reduce prblems with Verticillium and Fusarium wilt, cmmn sil-brne pathgens. Early hybrids were develped fr their yields and disease resistance. Flavr became a driving factr in the breeding f newer hybrids. Sme gardeners prefer t trade ff the disease prtectin f hybrids fr the rich tmatey flavrs f heirlm varieties. Fr early prductin, Early Girl is a ppular variety with mid-size fruits. Celebrity, Big By, and Better By are examples f ppular main seasn varieties. Many gardeners prefer the rich tmat flavr f heirlm Brandywine r the large beefsteak types. Pear tmates and yellw types are gaining ppularity. Cherry and the new grape-type tmates are ppular fr salads and snacking. Many, but nt all, have small size vines suitable fr cntainer gardening. [Figure 1] Figure 1. Sweet 100 is the mst ppular hme garden cherry-type tmat. On a large vine, it prduces hundreds f sweet, cherry sized fruits with very tender skins

2 Requiring less time t ck dwn, paste types such as Rma and its descendents are preferred fr making salsa, chili sauce, and ther tmat prducts. Be aware that paste types and standard varieties are nt directly interchangeable in recipes. Where the grwing seasn is shrt, select Early Girl and ther cultivars that will mature in 50 days r less. In many muntain cmmunities, tmates may nly be successfully grwn in a structure r adjacent t the suth side f a building t prvide frst prtectin and warmer grwing temperatures. Whatever type yu prefer, VFN resistant hybrid varieties are recmmended. The abbreviatin VFN indicates resistance t Verticillium wilt, Fusarium wilt, and nematdes. Verticillium and Fusarium wilts are cmmn sil-brne fungal diseases. Nematdes are nt an issue in Clrad due t cld sil temperatures. Researchers have fund multiple strains f Verticillium and Fusarium, s if yu are having prblems with these diseases, try ther VFN varieties. Vine types There are tw types f vines: indeterminant and determinant. Mst ppular hme garden varieties are indeterminant. The vine keeps grwing thrugh the grwing seasn, extending fruit prductin until frst kills the vine. Plant size is typically large. Determinant types are cmmn in cmmercial prductin as vine grwth stps when flwering begins; plants will typically be mderate in size. Determinant types put n a large single crp. They may be suitable fr cntainer planting where trellises are nt pssible. Planting Planting Time Fr ptimal grwing, tmates need warm temperatures: abve 52ºF at night and abve 60ºF during the day at transplant. They are readily killed by a light frst. A week f cl daytime temperatures (belw 55ºF) will stunt plants, reducing yields. With these warm temperature requirements, planting time alng the Clrad Frnt Range is typically late May. D nt plant tmates ut int a cld spell and make sure sil temperatures are warm. T get a head start n the seasn, gardeners use a variety f frst prtectin techniques. The Wall-f-Water prvides prtectin int the mid teens, r lwer. Cl sil temperatures als inhibit early grwth. When using a Wall-f-Water, als use black plastic mulch t help warm the sil. Be cautius in filling the Wallf-Water nt t splash water arund, as a wet sil will be slw t dry and warm in the spring. Fr additinal infrmatin n using plastic mulch, refer t the CMG GardenNtes #715, Mulches fr the Vegetable Garden. [Figure 2] Figure 2. Wall-f-Water prtects individual plants dwn t the mid-teens. Ntice that black plastic mulch was als used t warm the sil. Cl sil temperatures are als a grwth-limiting factr with early plantings

3 Selecting the Ideal Plants The ideal tmat transplant is dark grass green and six t eight inches tall. The stem is abut pencil size in diameter and the plant has nt been pruned r cut back. Transplants are hardened-ff (grwth rate slws s the plant is mre tlerant f the mve the greenhuse envirnment t the bright, windy utdrs) by withhlding water and/r nutrients r by expsure t cler temperature. Plant leggy transplants hrizntally When gardeners are shpping fr transplants in the warm greenhuse cnditins f May, tmat plants quickly grw frm ideal size t tall and leggy. The white bumps alng the leggy tmat stem are rts beginning t frm. Plant these taller leggy transplants hrizntally. Dig a trench a tw t three inches deep. Place the plant hrizntal with nly the tp tw t three sets f leaves shwing abve the sil. Pinch ff ther lwer leaves belw the sil line befre planting. These leggy plants readily rt ut alng the stem in the warm sil near the surface, supprting rapid grwth. [Figure 3] Figure 3. Plant tall leggy tmates hrizntal in a shallw furrw. Space and Trellis Plants T minimize Early Blight, space and trellis plants t allw fr gd air circulatin and prmte rapid drying. Trellised tmates are easier t pick and less preferred by tmat psyllid insects. Trellising eliminates prblems with fruit rtting where they tuch the grund. The minimal spacing fr trellised tmates is tw feet apart in a hedgerw. Research has demnstrated that crwding plants will nt increase yields, but will increase disease prblems. Cages The American Sciety fr Hrticultural Science suggests a trellis tw feet in diameter by fur t five feet tall. It is easy t make frm a 6½-ft length f cncrete reinfrcing mesh. Cut ff the bttm ring f wire s the cages can be pushed int the grund. When a branch sticks ut f the cage, simple tuck it back in. [Figure 4] Fr the smaller-vined, determinant types, tw cages may be made frm a 6½-ft length, cutting the height in half. Cages will be tw feet diameter but nly 3-feet tall. Cmmercially available cages are t small fr mst ppular tmat varieties grwn n gd sils

4 Figure 4. Tmates planted in a raised bed with black plastic mulch and cages made frm cncrete reinfrcing mesh. Cages are six feet arund, tw feet acrss, and five feet tall. On imprved sils, tmat vines will lsely fill the cage, allwing fr gd air circulatin and easy picking. Tender transplants are rather sensitive t cl winds. Wrapping the cages with a plastic sheet r newspapers t prvide wind prtectin fr the first week helps plants acclimate. Figure 5. Wrapping the tmat cage with plastic r newspapers prtects tender plants frm cld winds. Single ple trellis Sme gardeners prefer t trellis tmates n a single ple r stake. T d this, prune plants t a single trunk by remving all side shts. This requires cnstant remval f side shts. Figure 6. Tmates trellised t a single ple. Fan trellis Anther methd, which prduces larger fruit, is t trellis t a three-trunk, fan shape, remving all ther side shts. This requires a sturdy frame t supprt the weight f the vine and fruit. Figure 7. Tmates trellised int a fan shape

5 Mulching As with any crp, surface mulch is recmmended t cnserve sil misture and manage weeds. Mulching helps reduce the splashing f Early Blight fungal spres frm the sil nt the leaves. It als helps stabilize sil misture levels, reducing the incidence f blssm end rt. Black plastic mulch is ppular fr tmates, warming the sil and pushing prductin tw t three weeks earlier. When using black plastic mulch, crps must be planted early s plant grwth cvers and shades the plastic befre summer heat sets in. Fr details, refer t the CMG GardenNtes #715, Mulches fr the Vegetable Garden. Irrigatin Avid verhead sprinkling n tmates. Fungal spres are easily water-splashed frm ne leaf t anther, and water n the leaves creates a favrable envirnment fr disease develpment. Watering in the mrning, allwing plants t dry befre nighttime, may als be helpful. Fr details n garden irrigatin, including drip irrigatin, refer t the CMG GardenNtes #714, Irrigating the Vegetable Garden. Fertilizatin Tmates have a lw nitrgen requirement. Under high nitrgen cnditins, vines grw excessively large at the expense f fruit prductin. Mre crrectly stated, tmates are a fussy nitrgen feeder. On sils lw in rganic matter, tmates typically run ut f nitrgen in mid-summer, reducing yields and predispsing the plants t Early Blight. At transplanting, apply ne t three applicatins (depending n sil rganic cntent) f a water-sluble, plant starter fertilizer. This includes any f the water-sluble prducts like MiracleGr, Peters, RapidGr, Schults, etc. Transplants wuld have been hardened ff (grwth slwed) in the greenhuse. Water-sluble fertilizers stimulate renewed grwth. If the weather turns cld late spring after tmates are ut (that is a week with daytime temperatures belw 55ºF), use water-sluble fertilizers t stimulate grwth when warm temperatures return. A week with daytime temperatures belw 55 ºF stunts tmat grwth, reducing yields. Mid-summer On lw rganic matter sils, tmates typically run ut f nitrgen in mid t late summer. Yellwing f the fliage, starting with lwer leaves, is the typical symptm f nitrgen stress. Lw nitrgen in the plant allws Early Blight disease t spread like wildfire. Keeping nitrgen levels up in mid t late summer is a primary means f Early Blight cntrl and significantly imprves yields. Fertilize tmates lightly as the first fruits reach tw-inches in diameter. Watersluble fertilizers (such as MiracleGr, RapidGr, and Peters) used accrding t label directins make a gd summer fertilizer supplement. Make applicatins every tw t fur weeks, depending n sil rganic cntent

6 If using a dry granular fertilizer, apply (ammnium sulfate) at the rate f ne level tablespn per plant. Sprinkle the granular fertilizer in a wide circle 12 t 20 inches ut frm the plant, and water in. Dry granular fertilizers can easily kill tmates if ver-applied. Fr additinal details n sil management and fertilizatin, refer t CMG GardenNtes #711, Vegetable Garden Sil Management and Fertilizatin. Pllinatin and Summer Temperatures Tmat pllinatin is temperature dependant. If nighttime temperatures drp belw 55ºF, pllen fails t develp and flwers that pen the fllwing mrning will nt set fruit. Cl nights ften interfere with fruit set fr early tmates and in higher elevatins. Blssm set sprays help set fruit even with cl nights. If the daytime temperature reaches 90ºF by 10 a.m., blssms that pened that mrning abrt. Blssm set sprays are nt effective under high temperatures. In July and August alng the Clrad Frnt Range, night temperatures have a 50/50 prbability f staying abve 55ºF any given night. In unusually warm seasns, tmat fruit set may be unusually high. When pr sil cnditins and/r watering prblems limit plant grwth ptential, fruit may ripen while small. With gd sil tilth and water cnditins, fruit size may be unusually large. Garden Sanitatin Cntrl weeds. Cmmn weeds harbr many garden insect and disease prblems. Vlunteer ptates and tmates culd be a surce f Early Blight infectin. [Figure 8] Fr Early Blight management, sme references suggest remving lwer leaves shwing symptms. Symptms start as tiny black spts n lwer leaves. Spts enlarge t light and dark target-like rings. Leaves yellw and the disease prgresses frm lwer leaves up the plant. If remving lwer leaves, fcus n leaves with the tiny black spts. Remving just the lwer yellw leaves will nt be adequate. Wash hands with sap and water immediately after tuching diseased leaves t prevent spreading spres t ther plants. Avid wrking with the plants when they are wet. Anther disease, tbacc msaic virus (TMV) can readily spread frm tbacc smke residues n the hands and clthing t tmates. Prevent TMV infectins by washing hands after smking r handling tbacc prducts. Figure 8. Early blight leaf spts [Pht: USDA] 717-6

7 Rtatin Since the cmmn tmat diseases (Early Blight, Verticillium and Fusarium wilt) are sil brne, crp rtatin is an effective management tl. Hwever, this may nt be practical in mst hme garden situatins, particularly since rtatin allws n tmates, peppers, ptates, eggplants, vine crps (cucumbers, squash, pumpkins, and melns), strawberries, r raspberries in the same grwing area fr at least fur years. In a garden bed, mving the tmates a few rws t the left r right is nt an effective rtatin. Fall Clean Up Remve all tmates and ptat debris in the fall. Dispse f debris in municipal trash r by burial. D nt cmpst unless the cmpst heats t at least 145ºF and the pile is turned ccasinally. Mst hme cmpst piles d nt heat adequately t kill pathgens. Cmmn Disrders Refer t the fllwing fact sheets available nline at CSU Extensin fact sheet #2.949, Recgnizing Tmat Prblems,, CMG GardenNtes #718, Tmat Early Blight, Figure 9. Blssm end rt n tmat is caused by water imbalance between the fruit and sil. The sil culd be t wet, t dry, r rt culd be cut by cultivatin. It culd be aggravated by sil cmpactin and pr sil preparatin. Ripening Fruit at the End f the Seasn T speed fruit ripening in the fall, hld back slightly n watering. Ripening Fruit Indrs With the frecast f a light frst, tmates may be prtected by cvering. If heavy frst is frecast and cvering is nt practical, harvest fruit befre the frst event and carry indrs. Pick ripening fruit and green tmates with a glssy green appearance that have reached abut three-furths f their full size. Remve stems. Wash fruit under a stream f water and allw t air dry n a clean twel. Save nly blemish-free fruits fr ripening indrs

8 As fr humidity, fruit shrivel if it is t lw. If the humidity is t high, fruit mld. A gardener will have t learn by trial and errr what wrks fr their hme. Sme gardeners simply hang the whle plant upside dwn in a dark cl barn r basement t let the fruits ripen gradually. In Clrad s dry climate, fruit tend t shrivel frm the lw humidity. Other ptins include placing tmates, ne r tw layers deep, in a cvered bx fr ripening. Sme peple find better success by individually wrapping fruit in newspaper r wax paper and placing them in a cvered bx. Placing a few fruit tgether in a vegetable strage bag has been effective fr thers. Fr higher humidity, place tmates up t tw layers deep in a blanching pan r strainer inside f a cvered pan with sme water in the bttm. Make sure the fruit des nt tuch the water. Ethylene gas prduced by ripening tmates is a ripening hrmne. T speed the ripening prcess, place a ripe tmat in the cntainer with the fruit. T slw the ripening f green tmates, rutinely remve ripening fruit frm the cntainer. Green fruit will ripen in abut tw weeks at 65ºF t 70ºF, and in abut three t fur weeks at 55ºF. Strage belw 50ºF will give fruit a bland, ff-flavr. Ripe tmates may be stred in the refrigeratr fr a few days. Additinal Infrmatin CMG GardenNtes n vegetable gardening: #711 Vegetable Garden: Sil Management #718 Early Blight f Tmates and Fertilizatin #719 Vegetable Garden Hints #712 Sample Vegetable Garden Seed Catalgs #720 Vegetable Planting Guide #713 Blck Style Layut in Raised Bed #721 Sample Planting fr Raised-Bed Garden Vegetable Gardens #722 Frst Prtectin and Extending the #714 Irrigating the Vegetable Garden Grwing Seasn #715 Mulches fr the Vegetable Garden #723 Grwing Vegetables in a Hbby Greenhuse #716 Water Cnservatin in the Vegetable Garden #724 Vegetable Gardening in Cntainers #717 Grwing Tmates Authrs: David Whiting (CSU Extensin, retired), with Carl O Meara (CSU Extensin, Bulder Cunty), and Carl Wilsn (CSU Extensin, retired). Artwrk by David Whiting; used by permissin. Clrad Master Gardener GardenNtes are available nline at Clrad Master Gardener training is made pssible, in part, by a grant frm the Clrad Garden Shw, Inc. Clrad State University, U.S. Department f Agriculture and Clrad cunties cperating. Extensin prgrams are available t all withut discriminatin. N endrsement f prducts mentined is intended nr is criticism implied f prducts nt mentined. Cpyright Clrad State University Extensin. All Rights Reserved. CMG GardenNtes may be reprduced, withut change r additins, fr nnprfit educatinal use. Revised Octber