<?xml version="1.0"?>

<ownershipDocument>

    <schemaVersion>X0201</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2003-10-14</periodOfReport>


    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000100893</issuerCik>
        <issuerName>UNION PLANTERS CORP</issuerName>
        <issuerTradingSymbol>upc</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001181809</rptOwnerCik>
            <rptOwnerName>SCHENCK STEVE J</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O UNION PLANTERS CORP</rptOwnerStreet1>
            <rptOwnerStreet2>6200 POPLAR AVE</rptOwnerStreet2>
            <rptOwnerCity>MEMPHIS</rptOwnerCity>
            <rptOwnerState>TN</rptOwnerState>
            <rptOwnerZipCode>38119</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>CEO Union Planters Bank IN</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>

        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2003-10-14</value>
            </transactionDate>
            <deemedExecutionDate>
                <value>2003-10-14</value>
            </deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>5800</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>33.48</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>60978</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>

        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2003-10-16</value>
            </transactionDate>
            <deemedExecutionDate>
                <value>2003-10-16</value>
            </deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>6750</value>
                    <footnoteId id="F2"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>33.2</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>67728</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>

    </nonDerivativeTable>

    <derivativeTable>

        <derivativeTransaction>
            <securityTitle>
                <value>Emp. Stock Option (right to buy)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>33.48</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2003-10-14</value>
            </transactionDate>
            <deemedExecutionDate>
                <value>2003-10-14</value>
            </deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>93750</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>33.48</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <value>2004-10-14</value>
                <footnoteId id="F3"/>
            </exerciseDate>
            <expirationDate>
                <value>2013-10-14</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>93750</value>
                    <footnoteId id="F3"/>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>93750</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>

    </derivativeTable>

    <footnotes>
        <footnote id="F1">Grant of restricted stock acquired under the 1992 Stock Option Incentive Plan.  Restriction lapses in 1/6 annual increments for a six year period.</footnote>
        <footnote id="F2">Grant of restricted stock acquired under the Executive Performance Restricted Stock Plan.  Restriction lapses in 1/6 annual increments for a six year period.</footnote>
        <footnote id="F3">The option becomes exerciseable in three equal installments on October 14, 2004, 2005 and 2006.</footnote>
    </footnotes>


    <ownerSignature>
        <signatureName>E. James House, Jr - Power of Attorney</signatureName>
        <signatureDate>2003-06-30</signatureDate>
    </ownerSignature>

</ownershipDocument>
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X0201
4
2003-10-14
0
0000100893
UNION PLANTERS CORP
upc
0001181809
SCHENCK STEVE J
C/O UNION PLANTERS CORP
6200 POPLAR AVE
MEMPHIS
TN
38119
0
1
0
0
CEO Union Planters Bank IN
Common Stock
2003-10-14
2003-10-14
4
A
0
5800
33.48
A
60978
D
Common Stock
2003-10-16
2003-10-16
4
A
0
6750
33.2
A
67728
D
Emp. Stock Option (right to buy)
33.48
2003-10-14
2003-10-14
4
A
0
93750
33.48
A
2004-10-14
2013-10-14
Common Stock
93750
93750
D
Grant of restricted stock acquired under the 1992 Stock Option Incentive Plan.  Restriction lapses in 1/6 annual increments for a six year period.
Grant of restricted stock acquired under the Executive Performance Restricted Stock Plan.  Restriction lapses in 1/6 annual increments for a six year period.
The option becomes exerciseable in three equal installments on October 14, 2004, 2005 and 2006.
E. James House, Jr - Power of Attorney
2003-06-30