<PAGE>
                                                                 EXHIBIT 4(m)(2)


                               THE SCOTTS COMPANY

                                  $400,000,000

                              SERIES A AND SERIES B
                    8.625% SENIOR SUBORDINATED NOTES DUE 2009


                        --------------------------------


                             SUPPLEMENTAL INDENTURE

                          Dated as of February 6, 2002

                                       to

                                    INDENTURE

                          Dated as of January 21, 1999

                        --------------------------------


                      STATE STREET BANK AND TRUST COMPANY,

                                   as Trustee
<PAGE>
                             SUPPLEMENTAL INDENTURE

            SUPPLEMENTAL INDENTURE (the "Supplemental Indenture") dated as of
February 6, 2002 by and among The Scotts Company, an Ohio corporation (the
"Company"), Scotts Manufacturing Company ("Scotts Manufacturing," as successor
by merger to Scotts Miracle-Gro Products, Inc.), Scotts Temecula Operations, LLC
("Scotts Temecula", as successor by merger to Republic Tool & Manufacturing
Corp.) and the other guarantors named on the signature pages hereto
(collectively with Scotts Manufacturing and Scotts Temecula, the "Guarantors")
and State Street Bank and Trust Company, as trustee (the "Trustee"). Capitalized
terms used but not defined herein shall have the meanings assigned to such terms
in the Indenture (as defined below).

                               W I T N E S S E T H

            WHEREAS, the Company, the Guarantors (including the predecessors of
Scotts Manufacturing and Scotts Temecula) and the Trustee previously duly
executed, and the Company and the Guarantors (including the predecessors of
Scotts Manufacturing and Scotts Temecula) duly delivered to the Trustee, an
Indenture (the "Indenture") dated as of January 21, 1999 providing for the
issuance of an aggregate principal amount of up to $400,000,000 of 8.625% Senior
Subordinated Notes due 2009 (the "Notes");

            WHEREAS, the Company previously issued $330,000,000 of the Notes as
of January 21, 1999 (the "Initial Notes") and now wishes to issue the remaining
$70,000,000 of the Notes permitted to be issued under the Indenture (the
"Additional Notes");

            WHEREAS, a supplemental indenture is required to be entered into in
connection with the merger of Guarantors pursuant to Section 11.05;

            WHEREAS, the Company desires to amend certain provisions to provide
for the issuance of Additional Notes;

            WHEREAS, the Indenture provides that a Subsidiary required to
execute a Guarantee of the Notes shall execute and deliver a supplemental
indenture to the Trustee in connection therewith;

            WHEREAS, the Board of Directors of the Company has authorized the
execution of this Supplemental Indenture and its delivery to the Trustee;

            WHEREAS, the Company has delivered an Officers' Certificate and an
Opinion of Counsel to the Trustee pursuant to Sections 7.02 and 13.04 of the
Indenture; and

            WHEREAS, all other actions necessary to make this Supplemental
Indenture a legal, valid and binding obligation of the parties hereto in
accordance with its terms and the terms of the Indenture have been performed;

            NOW, THEREFORE, in consideration of the foregoing and for other good
and valuable consideration, the receipt of which is hereby acknowledged, the
Guarantors, the
<PAGE>
                                                                               2


Company and the Trustee mutually covenant and agree for the equal and ratable
benefit of the Holders of the Notes as follows:

            1. Amendments to Indenture.

                  I. Section 1.01 of the Indenture shall be amended as follows:

                  (a) by deleting the definition of "Additional Notes" and
substituting in lieu thereof the following:

                  "Additional Notes" means up to $70.0 million in aggregate
principal amount of Notes (other than the Initial Notes) issued under this
Indenture in accordance with Sections 2.02 and 4.09 hereof.

                  (b) by deleting the definition of "Initial Notes" and
substituting in lieu thereof the following:

                  "Initial Notes" means $330.0 million in aggregate principal
amount of Notes issued under this Indenture on January 21, 1999.

                  (c) by deleting the definition of "Initial Purchaser" and
substituting in lieu thereof the following:

                  "Initial Purchaser" shall have the meaning assigned to such
term in the Offering Memoranda.

                  (d) by deleting the definition of "Liquidated Damages" and
substituting in lieu thereof the following:

                  "Liquidated Damages" means all amounts owing pursuant to the
Registration Rights Agreement.

                  (e) by deleting the definition of "Offering Memorandum" and
substituting in lieu thereof the following:

                  "Offering Memoranda" means the Offering Memorandum, dated
January 21, 1999, pursuant to which the Initial Notes were offered and sold, and
the Offering Memorandum, dated February 1, 2002, pursuant to which the
Additional Notes were offered and sold.

                  II. Exhibits A-1 and A-2 to the Indenture shall be amended as
follows:

                  (a) by deleting the first sentence of Section 1 in Exhibit A-1
and in Exhibit A-2 entitled "Interest" and substituting in lieu thereof the
following:

                  "The Scotts Company, an Ohio corporation (the "Company"),
promises to pay interest on the principal amount of this Note at 8.625% per
annum from February 6, 2002 until maturity and shall pay the Liquidated Damages
payable pursuant to the Registration Rights Agreement."
<PAGE>
                                                                               3


                  (b) by deleting the third sentence of Section 1 in Exhibit A-1
and in Exhibit A-2 entitled "Interest" and substituting in lieu thereof the
following:

            "Interest on the Notes shall accrue from the most recent date to
which interest has been paid or, if no interest has been paid, from the date of
issuance; provided that if there is no existing Default in the payment of
interest, and if this Note is authenticated between a record date referred to on
the face hereof and the next succeeding Interest Payment Date, interest shall
accrue from such next succeeding Interest Payment Date; provided, further, that
the first Interest Payment Date shall be July 15, 2002."

            2. Issuance of Additional Notes and Guarantees. The Company agrees
to issue the Additional Notes and the Guarantors each agree to unconditionally
guarantee all of the Company's obligations under the Notes, in each case in
accordance with the terms and conditions set forth in the Indenture.

            3. Agreement to Guarantee by Guarantors. Each Guarantor hereby
agrees as follows:

            (a) Along with the other Guarantors, to jointly and severally
            Guarantee to each Holder of a Note authenticated and delivered by
            the Trustee and to the Trustee and its successors and assigns
            irrespective of the validity and unenforceability of the Indenture,
            the Notes or the obligations of the Company hereunder or thereunder,
            that:

                  (i)   the principal of and interest on the Notes will be
                        promptly paid in full when due, whether at maturity, by
                        acceleration, redemption or otherwise, and interest on
                        the overdue principal of and interest on the Notes, if
                        any, if lawful, and all other obligations of the Company
                        to the Holders or the Trustee hereunder or thereunder
                        will be promptly paid in full or performed, all in
                        accordance with the terms hereof and thereof; and

                  (ii)  in case of any extension of time of payment or renewal
                        of any Notes or any of such other obligations, that same
                        will be promptly paid in full when due or performed in
                        accordance with the terms of the extension or renewal,
                        whether at stated maturity, by acceleration or
                        otherwise. Failing payment when due of any amount so
                        guaranteed or any performance so guaranteed for whatever
                        reason, the Guarantors shall be jointly and severally
                        obligated to pay the same immediately.

            (b) The obligations hereunder shall be unconditional, irrespective
            of the validity, regularity or enforceability of the Notes or the
            Indenture, the absence of any action to enforce the same, any waiver
            or consent by any Holder of the Notes with respect to any provisions
            hereof or thereof, the recovery of any judgment against the Company,
            any action to enforce the same or any other circumstance which might
            otherwise constitute a legal or equitable discharge or defense of a
            guarantor.
<PAGE>
                                                                               4


            (c) The following is hereby waived: diligence, presentment, demand
            of payment, filing of claims with a court in the event of insolvency
            or bankruptcy of the Company, any right to require a proceeding
            first against the Company, protest, notice and all demands
            whatsoever.

            (d) The Subsidiary Guarantees shall not be discharged except by
            complete performance of the obligations contained in the Notes and
            the Indenture, and each Guarantor accepts all obligations of an
            Initial Guarantor under the Indenture.

            (e) If any Holder or the Trustee is required by any court or
            otherwise to return to the Company, the Guarantors, or any
            Custodian, Trustee, liquidator or other similar official acting in
            relation to either the Company or the Guarantors, any amount paid by
            either to the Trustee or such Holder, the Subsidiary Guarantees, to
            the extent theretofore discharged, shall be reinstated in full force
            and effect.

            (f) Each Guarantor shall not be entitled to any right of subrogation
            in relation to the Holders in respect of any obligations guaranteed
            hereby until payment in full of all obligations guaranteed hereby.

            (g) As between the Guarantors, on the one hand, and the Holders and
            the Trustee, on the other hand, (x) the maturity of the obligations
            guaranteed hereby may be accelerated as provided in Article 6 of the
            Indenture for the purposes of the Guarantees of all of the Company's
            Obligations under the Notes and the Indenture (the "Subsidiary
            Guarantees"), notwithstanding any stay, injunction or other
            prohibition preventing such acceleration in respect of the
            obligations guaranteed hereby, and (y) in the event of any
            declaration of acceleration of such obligations as provided in
            Article 6 of the Indenture, such obligations (whether or not due and
            payable) shall forthwith become due and payable by the Guarantors
            for the purpose of the Subsidiary Guarantees.

            (h) The Guarantors shall have the right to seek contribution from
            any non-paying Guarantor so long as the exercise of such right does
            not impair the rights of the Holders under the Guarantee.

            (i) The obligations hereunder shall be subject to the subordination
            provisions of the Indenture.

            4. Execution and Delivery. Each Guarantor agrees that the Subsidiary
Guarantees shall remain in full force and effect notwithstanding any failure to
endorse on each Note a notation of such Subsidiary Guarantee.

            5. Guarantor May Consolidate, Etc. on Certain Terms.

            (a) Each Guarantor may not consolidate with or merge with or into
            (whether or not such Guarantor is the surviving Person) another
            corporation, Person or entity whether or not affiliated with such
            Guarantor unless:

                  (i)   subject to Sections 11.05 of the Indenture, the Person
                        formed by or surviving any such consolidation or merger
                        (if other than a
<PAGE>
                                                                               5


                        Guarantor or the Company) unconditionally assumes all
                        the obligations of such Guarantor, pursuant to a
                        supplemental indenture in form and substance reasonably
                        satisfactory to the Trustee, under the Notes, the
                        Indenture and the Subsidiary Guarantee on the terms set
                        forth herein or therein; and

                  (ii)  immediately after giving effect to such transaction, no
                        Default or Event of Default exists.

            (b) In case of any such consolidation, merger, sale or conveyance
            and upon the assumption by the successor corporation, by
            supplemental indenture, executed and delivered to the Trustee and
            satisfactory in form to the Trustee, of the Subsidiary Guarantees
            endorsed upon the Notes and the due and punctual performance of all
            of the covenants and conditions of the Indenture to be performed by
            the Guarantor, such successor corporation shall succeed to and be
            substituted for the Guarantor with the same effect as if it had been
            named herein as a Guarantor. Such successor corporation thereupon
            may cause to be signed any or all of the Subsidiary Guarantees to be
            endorsed upon all of the Notes issuable hereunder which theretofore
            shall not have been signed by the Company and delivered to the
            Trustee. All the Subsidiary Guarantees so issued shall in all
            respects have the same legal rank and benefit under the Indenture as
            the Subsidiary Guarantees theretofore and thereafter issued in
            accordance with the terms of the Indenture as though all of such
            Subsidiary Guarantees had been issued at the date of the execution
            hereof.

            (c) Except as set forth in Articles 4 and 5 and Section 11.05 of
            Article 11 of the Indenture, and notwithstanding clauses (a) and (b)
            above, nothing contained in the Indenture or in any of the Notes
            shall prevent any consolidation or merger of a Guarantor with or
            into the Company or another Guarantor, or shall prevent any sale or
            conveyance of the property of a Guarantor as an entirety or
            substantially as an entirety to the Company or another Guarantor.

            6. Releases.

            (a) In the event of a sale or other disposition of all of the assets
            of any Guarantor, by way of merger, consolidation or otherwise, or a
            sale or other disposition of all of the capital stock of any
            Guarantor, then such Guarantor (in the event of a sale or other
            disposition, by way of merger, consolidation or otherwise, of all of
            the capital stock of such Guarantor) or the corporation acquiring
            the property (in the event of a sale or other disposition of all or
            substantially all of the assets of such Guarantor) will be released
            and relieved of any obligations under its Subsidiary Guarantee;
            provided that the Net Proceeds of such sale or other disposition are
            applied in accordance with the applicable provisions of the
            Indenture, including without limitation Section 4.10 of the
            Indenture. Upon delivery by the Company to the Trustee of an
            Officers' Certificate and an Opinion of Counsel to the effect that
            such sale or other disposition was made by the Company in accordance
            with the provisions of the Indenture, including without limitation
            Section 4.10 of the Indenture, the Trustee
<PAGE>
                                                                               6


            shall execute any documents reasonably required in order to evidence
            the release of any Guarantor from its obligations under its
            Subsidiary Guarantee.

            (b) Any Guarantor not released from its obligations under its
            Subsidiary Guarantee shall remain liable for the full amount of
            principal of and interest on the Notes and for the other obligations
            of any Guarantor under the Indenture as provided in Article 11 of
            the Indenture.

            7. No Recourse Against Others. No past, present or future director,
officer, employee, incorporator, stockholder or agent of each Guarantor, as
such, shall have any liability for any obligations of the Company or any
Guarantor under the Notes, any Subsidiary Guarantees, the Indenture or this
Supplemental Indenture or for any claim based on, in respect of, or by reason
of, such obligations or their creation. Each Holder of the Notes by accepting a
Note waives and releases all such liability. The waiver and release are part of
the consideration for issuance of the Notes. Such waiver may not be effective to
waive liabilities under the federal securities laws and it is the view of the
Securities and Exchange Commission that such a waiver is against public policy.

            8. NEW YORK LAW TO GOVERN. THE INTERNAL LAW OF THE STATE OF NEW YORK
SHALL GOVERN AND BE USED TO CONSTRUE THIS SUPPLEMENTAL INDENTURE TO THE EXTENT
THAT THE APPLICATION OF THE LAWS OF ANOTHER JURISDICTION WOULD BE REQUIRED
THEREBY.

            9. Counterparts The parties may sign any number of copies of this
Supplemental Indenture. Each signed copy shall be an original, but all of them
together represent the same agreement.

            10. Effect of Headings. The Section headings herein are for
convenience only and shall not affect the construction hereof.

            11. The Trustee. The Trustee accepts the amendment to the Indenture
effected by this Supplemental Indenture. Without limiting the generality of the
foregoing, the Trustee has no responsibility for the correctness of the recitals
of fact herein contained which shall be taken as the statements of the
Guarantors and the Company and makes no representations as to the validity or
sufficiency of this Supplemental Indenture, except as to the due and valid
execution hereof by the Trustee, and shall incur no liability or responsibility
in respect of the validity thereof.

            12. SUBSIDIARY GUARANTEES. Each of the Guarantors hereby affirms
that its Subsidiary Guarantee remains effective in all respects regardless of
the effect of this Supplement Indenture on the Indenture.

            13. Effect on Indenture. Upon execution of this Supplement
Indenture, the Indenture shall be modified in accordance herewith, but except as
expressly amended hereby, the Indenture is in all respects ratified and
confirmed and all the terms, conditions and provisions thereof shall remain in
full force and effect.
<PAGE>
                                                                               7


            14. Effect on Supplemental Indenture. Upon execution, this
Supplemental Indenture shall form a part of the Indenture and the Supplemental
Indenture and the Indenture shall be read, taken and construed as one and the
same instrument for all purposes, and every holder of Notes heretofore or
hereafter authenticated and delivered under the Indenture shall be bound hereby.
This Supplemental Indenture shall become effective as of the date first above
written.
<PAGE>
                                                                               8


            IN WITNESS WHEREOF, the parties hereto have caused this Supplemental
Indenture to be duly executed and attested, all as of the date first above
written.

<TABLE>
<S>                                    <C>
                                       The Scotts Company

                                       By:  /s/ Patrick J. Norton
                                          ------------------------------------
                                       Name:  Patrick J. Norton
                                       Title: Executive Vice President and CFO

                                       GUARANTORS:

                                       Scotts Manufacturing Company, as
                                       successor by merger to Scotts Miracle-Gro
                                       Products Inc.

                                       By:  /s/ Patrick J. Norton
                                          ------------------------------------
                                       Name:  Patrick J. Norton
                                       Title: Executive Vice President and CFO

                                       Scotts Temecula Operations, LLC, as
                                       successor by merger to Republic Tool &
                                       Manufacturing Corp.

                                       By:  /s/ Patrick J. Norton
                                          ------------------------------------
                                       Name:  Patrick J. Norton
                                       Title: Executive Vice President and CFO

                                       Miracle-Gro Lawn Products, Inc.


                                       By: /s/ Patrick J. Norton
                                          ------------------------------------
                                       Name:  Patrick J. Norton
                                       Title: Executive Vice President and CFO

                                       OMS Investments, Inc.


                                       By: /s/ Patrick J. Norton
                                           -----------------------------------
                                       Name:  Patrick J. Norton
                                       Title: Executive Vice President and CFO
</TABLE>
<PAGE>
                                                                               9


<TABLE>
<S>                                    <C>
                                       Hyponex Corporation

                                       By: /s/ Patrick J. Norton
                                          ------------------------------------
                                       Name:  Patrick J. Norton
                                       Title: Executive Vice President and CFO

                                       EarthGro, Inc.

                                       By: /s/ Patrick J. Norton
                                          ------------------------------------
                                       Name:  Patrick J. Norton
                                       Title: Executive Vice President and CFO

                                       Scotts Products Company

                                       By: /s/ Patrick J. Norton
                                          ------------------------------------
                                       Name:  Patrick J. Norton
                                       Title: Executive Vice President and CFO

                                       Scotts Professional Products Co.

                                       By: /s/ Patrick J. Norton
                                          ------------------------------------
                                       Name:  Patrick J. Norton
                                       Title: Executive Vice President and CFO

                                       Scotts-Sierra Horticultural
                                       Products Company

                                       By: /s/ Patrick J. Norton
                                          ------------------------------------
                                       Name:  Patrick J. Norton
                                       Title: Executive Vice President and CFO

                                       Scotts-Sierra Crop Protection Company

                                       By: /s/ Patrick J. Norton
                                          ------------------------------------
                                       Name:  Patrick J. Norton
                                       Title: Executive Vice President and CFO
</TABLE>
<PAGE>
                                                                              10

<TABLE>
<S>                                    <C>
                                       Scotts-Sierra Investments, Inc.

                                       By: /s/ Patrick J. Norton
                                          ------------------------------------
                                       Name:  Patrick J. Norton
                                       Title: Executive Vice President and CFO

                                       Swiss Farms Products, inc.

                                       By: /s/ Patrick J. Norton
                                          ------------------------------------
                                       Name:  Patrick J. Norton
                                       Title: Executive Vice President and CFO


State Street Bank and Trust Company,
As Trustee

By: /s/ Cauna M. Silva
   ---------------------------------
Name:  Cauna M. Silva
Title: Vice President
</TABLE>