<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0303</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2008-12-09</periodOfReport>

    <issuer>
        <issuerCik>0000737758</issuerCik>
        <issuerName>TORO CO</issuerName>
        <issuerTradingSymbol>TTC</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001209369</rptOwnerCik>
            <rptOwnerName>MEURLOT SANDRA J</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>8111 LYNDALE AVENUE SOUTH</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>BLOOMINGTON</rptOwnerCity>
            <rptOwnerState>MN</rptOwnerState>
            <rptOwnerZipCode>55420-1196</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>Vice President, Operations</officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2008-12-09</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>2163</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>6800</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2008-12-09</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>F</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>707</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>31.28</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>6093</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Performance Share Units</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>50758.984</value>
                    <footnoteId id="F2"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>647.251</value>
                    <footnoteId id="F3"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>The Toro Company Investment, Savings &amp; ESOP</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes>
        <footnote id="F3">Includes the following shares of common stock acquired by the reporting person under the dividend reinvestment feature of The Toro Company Investment, Savings &amp; ESOP Plan since the date of her last report:  1.1764 shares acquired on January 11, 2008, 2.328 shares acquired on April 11, 2008, 3.105 shares acquired on July 11, 2008, and 3.012 shares  acquired on October 17, 2008.  Also includes an account adjustment (rounding) of .0007 shares of common stock and 68.091 shares of common stock acquired on February 28, 2008 through issuer contributions to The Toro Company Investment, Savings &amp; ESOP.</footnote>
        <footnote id="F1">Represents payout of Performance Share Awards for the Fiscal 2006 to Fiscal 2008 Performance Period under The Toro Company Performance Share Plan (the &quot;PSP&quot;), as approved by the registrant's Compensation &amp; Human Resources Committee of its Board of Directors subject to confirmation by the registrant's Fiscal 2008 financial results released on December 9, 2008.  Performance Share Awards are paid in shares of common stock under the PSP.</footnote>
        <footnote id="F2">Includes the following Performance Share Units acquired by the reporting person under the dividend reinvestment feature of The Toro Company Deferred Compensation Plan for Officers since the date of her last report: 158.622 Performance Share Units acquired on January 11, 2008, 181.822 Performance Share Units acquired on April 11, 2008, 244.133 Performance Share Units acquired on July 11, 2008, and 234.916 Performance Share Units acquired on October 17, 2008.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>Stacy L. Bogart, Atty-In-Fact</signatureName>
        <signatureDate>2008-12-11</signatureDate>
    </ownerSignature>
</ownershipDocument>
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X0303
4
2008-12-09
0000737758
TORO CO
TTC
0001209369
MEURLOT SANDRA J
8111 LYNDALE AVENUE SOUTH
BLOOMINGTON
MN
55420-1196
0
1
0
0
Vice President, Operations
Common Stock
2008-12-09
4
A
0
2163
0
A
6800
D
Common Stock
2008-12-09
4
F
0
707
31.28
D
6093
D
Performance Share Units
50758.984
D
Common Stock
647.251
I
The Toro Company Investment, Savings & ESOP
Includes the following shares of common stock acquired by the reporting person under the dividend reinvestment feature of The Toro Company Investment, Savings & ESOP Plan since the date of her last report:  1.1764 shares acquired on January 11, 2008, 2.328 shares acquired on April 11, 2008, 3.105 shares acquired on July 11, 2008, and 3.012 shares  acquired on October 17, 2008.  Also includes an account adjustment (rounding) of .0007 shares of common stock and 68.091 shares of common stock acquired on February 28, 2008 through issuer contributions to The Toro Company Investment, Savings & ESOP.
Represents payout of Performance Share Awards for the Fiscal 2006 to Fiscal 2008 Performance Period under The Toro Company Performance Share Plan (the "PSP"), as approved by the registrant's Compensation & Human Resources Committee of its Board of Directors subject to confirmation by the registrant's Fiscal 2008 financial results released on December 9, 2008.  Performance Share Awards are paid in shares of common stock under the PSP.
Includes the following Performance Share Units acquired by the reporting person under the dividend reinvestment feature of The Toro Company Deferred Compensation Plan for Officers since the date of her last report: 158.622 Performance Share Units acquired on January 11, 2008, 181.822 Performance Share Units acquired on April 11, 2008, 244.133 Performance Share Units acquired on July 11, 2008, and 234.916 Performance Share Units acquired on October 17, 2008.
Stacy L. Bogart, Atty-In-Fact
2008-12-11